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PHYSIOLOGY - Last moment revisions
Muscle Physiology
·Muscle form 40 to 50% of body mass.
·About 600 muscles are identified.
Classification of Muscles:
·Depending on striations: Striated(Skeletal & Cardiac) & Nonstriated(smooth)
·Depending on Control: voluntary(Skeletal) & Involuntary(Cardiac & smooth)
·Depending on situation: Skeletal, Cardiac & Smooth.
·Muscle fiber or cell has a length b/w 1 – 4cm (Average 3cm) & diameter from 10 –
100microns.
·1 myofibril contains 1500 myosin filaments & 3000 actin filaments
·Sarcomere is the structural & functional unit of skeletal muscle.
 Length – 2.5 to 3.2 mm.
 Sarcomere lies b/w two ‘Z’ lines
·Each myofibril consists of alternate light (I or J band) & dark band (A or Q band).
·Each sarcomere consist of thin (Actin) & thick (myosin) filaments.
Myosin filament is present throughout the ‘A’ band.
No movement of myosin during muscular contraction.
·Actin filaments are formed by 3 types of proteins called actin, tropomyosin & troponin.
·The skeletal muscle is formed by 75% of water, 20% of proteins & 5%of organic
substances.
·Troponin: is formed by 3 subunits; Troponin I – attached to F actin; Troponin T – attached
to tropomyosin; Troponin C – attached to calcium ions.
·Following are the muscle proteins; Myosin; Actin; Tropomyosin; Troponin; Actinin; Titin;
Desmin; Myogen & Myoglobulin.
·There is no movement in the myosin filament during muscle contraction.
·Actin filaments slide over the myosin filament during muscle contraction.
·Tropomyosin covers the active sites of actin.
·Rheobase: this is the least possible, i.e. (minimum) strength (Voltage) of stimulus which
can excite the tissue.
·Chronaxie: it is the minimum time, at which a stimulus with double the rheobasic strength
(voltage) can excite the tissue.
Chronaxie of skeletal muscle is shorter than that of cardiac and smooth muscles.
Cold lengthens chronaxie. whereas vagal stimulation shortens chronaxie.


                                                                                              1
·Refractory period is the period at which the muscle does not show any response to a
stimulus.
·Skeletal muscles are purely aerobic & don’t have any fuel reserve.
·Dark, light bands & troponin are absent in smooth muscle.
·The study of electrical activity of the muscle is done by electromyography.
·The muscle ruptures when it is stretched to about 3 times its equilibrium length.


Cardiovascular system
   ·The syncytium of called physiological syncytium because there is no anatomical
       continuity of the fibers.
   ·SA node the pace maker is a small strip of modified cardiac muscle is situated in the
       superior part of lateral wall of right
     atrium, just below the opening of superior vena cava.
   · AV node is situated in the right posterior portion of interatrial septum.
   · Bundle of his run on either side of the interventricular septum.
   · Rhythmicity of different parts of heart:
            o SA node                    : 70 to 80 / min
            o AV node                    : 40 to 60 / min
            o Atrial muscle              : 40 to 60 / min
            o Ventricular muscle         : 20 to 40 / min
   · Velocity of impulse at different parts of the conductive system.
            o Atrial muscle fibres       : 0.3 meter / second
            o Internodal fibers          : 1.0 meter / second
            o AV node                    : 0.05 meter / second
            o Bundle of his              : 0.12 meter / second
            o Purkinje fibers            : 4 meter / second
            o Ventricular muscle fibers : 0.5 meter / second
   · Cardiac cycle includes systole & diastole which practically includes the events of
       ventricles.
   · When heart beats at the normal rate of 72/min, the duration of cardiac cycle is 0.8
       sec.
   · The duration of systole is 0.27 sec & that of diastole is 0.53 sec.
   · The subdivision with duration are
            o Systole
                     §   Isometric contraction   = 0.05 sec


                                                                                        2
§   Ejection period   = 0.22 sec
       o Diastole
                §   Protodiastole             = 0.04 sec
                §   Isometric relaxation      = 0.08 sec
                §   Rapid filling             = 0.11 sec
                §   Slow filling              = 0.19 sec
                §   Atrial systole            = 0.11 sec
                §   Total duration of cardiac cycle = 0.27 + 0.53 = 0.8 sec.
· Atrial systole: atrial contract & a small amount of blood enter the ventricles.
· Isometric contraction: all the valves are closed, ventricles undergo isometric
   contraction & pressure in the ventricles
is increased.
· Ejection period: semilunar valves opened, ventricles contract & blood is ejected out.
· Protodiastole: this is the first diastole. The semilunar valves are closed at the end of
   this period.
· Isometric relaxation: all the valves are closed, ventricles undergo isometric
   relaxation & pressure in the ventricles is reduced.
· Rapid & slow filling: Atrioventricular valves are opened, ventricles relax & filling
   occurs.
· Pressure difference
      Pressure      Right    Left     Right        Left        Systemic   Pulmonary
                    Atrium   Atrium   Ventricle    Ventricle   Aorta      artery
      Max
      (mm of        5–6      7–8      25           120         120        25
      Hg)
      Min
      (mm of        0–2      0–2      2–3          5           80         7–8
      Hg)
· End systolic volume is 70 – 90 ml
· End diastolic volume is 130 – 150 ml.




                                                                                          3
· Cause for cardiac murmurs
       Systolic murmur                          Diastolic murmur               Continuous
                                                                               murmur
       1.        Incompetence of AV             1.    Stenosis of AV valve     Patent
               valve                            2.      Incompetence     of    ductus
       2.              Stenosis         of           semilunar valves          arteiosus
               semilunar valves
       3.       Anemia
       4.       Septal defect
       5.       Coarctation of aorta
· Electrocardiography:
       Duration
       o       Interval B/W 2 thick lines: (5mm) = 0.2 second
       o       Interval B/W 2 thin lines (1mm) = 0.04 second
       Amplitude
       o       Interval B/W 2 thick lines: (5mm) = 0.5 mV
       o       Interval B/W 2 thin lines (1mm) = 0.1 mV
       Speed of the paper
       o       25 mm or 50 mm / second
   §   Normal heart rate is 72 / min
   §   Tachycardia: increase heart rate above 100 / min.
       Waves of normal ECG
   Wave          /     From – to       Cause                     Duration        Amplitude
   segment                                                       (second)        (mV)
                                       Atrial                    0.1             0.1 to 0.12
   P wave              -
                                       depolarization
                                       Ventricular               0.08 – 0.10     Q=0.1 – 0.2
   QRS
                       -               repolarization                            R=1
   complex
                                                                                 S=0.4
                                       Ventricular               0.2             0.3
   T wave              -
                                       repolarzation
                       Onset of P      Atrial                    0.18 (0.12 to
   P       –     R     wave       to   depolarization        &   0.2)
                                                                                 -
   interval            onset of Q      conduction through
                       wave            AV node

                                                                                               4
Onset of Q              Electrical activity in     0.4 – 0.42
   Q       –   T   wave           &        ventricles.
                                                                                       -
   interval        end     of     T
                   wave
                   End     of     S                                   0.08
   ST              wave           &
                                           -                                           -
   segment         onset of T
                   wave
· In hyperkalemia, ECG shows a tall T wave.
· In hypokalemia, ECG shows depressed S-T segment.
· Heart sounds.
   Heart       Occurs                 Cause               Characteristics      Duration    Relation
   sounds      during                                                          (sec)       to ECG
   First       Isometric              Closure       of    Long, soft, &        0.10    –   ‘R’ wave
               contraction            AV valves           low       pitched.   0.17
               &     ejection                             Resembles the
               period                                     word ‘LUBB’
   Second      Protodiastole          Closure       of    Short,     sharp,    0.10    –   Precedes
               &   part      of       semilunar           & high pitched.      014         or
               isometric              valves              Resembles the                    appears
               relaxation                                 word ‘DUBB’                      0.09 sec
                                                                                           after
                                                                                           summit
                                                                                           of      ‘T’
                                                                                           wave
   Third       Rapid filling          Rushing       of    Low pitched          0.07    –   B/W      ‘P’
                                      blood       into                         0.1         wave      &
                                      ventricles                                           ‘Q’
                                                                                           wave.
   Fourth      Atrial systole         Contraction         Inaudible            0.02    –   B/W      ‘P’
                                      of         atrial   sound                0.04        wave      &
                                      musculature                                          ‘Q’ wave
   §    Bradycardia: decrease in rate below 60 / min.




                                                                                                          5
·Arrhythmia: irregular heart beat.
   §   Sinus tachycardia: increase in discharge of impulse from SA node, upto 100 /
       min
   §   Sinus bradycardia: reduction in the impulses from SA node, about 40 / min
   §   Atrial flutter: Atrial rate is about 250 – 350 / min
   §   Atrial fibrillation: rate of 300 – 400 beats / min
   §   Ventricular fibrillation: rate is about 400 – 500 / min
   §   Bain Bridge reflex (venous reflex) is characterized by reflex increase in Heart
       rate on venous engorgement of the
    right atrium.
   §    Mary's law states that the Heart rate and Blood pressure have inverse
       relationship.
   §    Stokes Adams syndrome is characterized by repeated fainting attacks
       associated with complete heart block.
· Cardiac Output:
       o     The amount of blood pumped from each ventricle.
· Stroke volume: the amount of blood pumped out by each ventricle during each beat -
   70ml.
       o     Stroke volume at rest is 80 - 100 ml.
· Minute volume: amount of blood pumped out by each ventricle in one minute. Minute
   volume = stroke volume X heart
rate. – 5 liters/per ventricle/minute.
· Cardiac Index: the minute volume from ventricle expressed in relation to square
   meter of body surface area. Normal
value: 2.8 ± 0.3 liters / 1 square meter of body surface area / minute.
· Ejection fraction: the fraction of end diastolic volume that is ejected out by each
   ventricle. Normal – 60 to 65%.
· Cardiac reserve: the maximum amount of blood that can be pumped out by the heart
   above normal value. Normal
healthy adult: 300 – 400%.
· Variations in Cardiac output: (Physiological)
       o     Less in children, females, early morning, changing from recumbent to upright
           position & in sleep.
       o     Increased in males, greater body build, day time, emotional upset, after
           meals, after exercise, high attitude,


                                                                                        6
and later months of pregnancy.
· Distribution of Cardiac output:
       Organ                    Amount of blood           Percentage
       Liver                    1500ml                    30%
       Kidney                   1300ml                    26%
       Skeletal muscles         900ml                     18%
       Brain                    800ml                     16%
       Skin, bone & GIT         300ml                     6%
       Heart                    200ml                     4%
       Total                    5000ml                    100%
· Factors maintaining Cardiac output:
      1.        Venous return
            §    Respiratory pump; Muscle pump; Gravity; Venous pressure; Vasomotor
                 tone.
      2.        Force of contraction
      3.        Heart rate
      4.        Peripheral resistance
· Regulation of Heart rate:
      1.        Vasomotor center: bilaterally situated in the reticular formation of medulla
            oblongata & lower part of pons.
      2.        Motor nerve fiber of heart.
      3.        sensory nerve fiber
· Haemodynamics:
    Factors maintaining volume of flow of blood.
        ·       Pressure gradient; Resistance to blood flow; Viscosity of blood; Diameter of
            blood vessels; Velocity of blood flow:
· Arterial Blood pressure:
   · Systolic pressure: maximum pressure exerted in the arteries during the systole of
      heart. Normal: 120 mmHg.
   (range 110 – 140)
   · Diastolic Blood Pressure: minimum pressure in the arteries during the diastole of
      the heart. Normal: 80 mmHg
   (range 60 – 90)
   · Pulse pressure: Difference between the systolic pressure & diastolic pressure.
      Normal: 40 mmHg.

                                                                                           7
· Mean arterial blood pressure: this is the diastolic pressure plus one-third of
        pulse pressure. Normal: 93 mmHg.
   · Variations (Physiological)
        o    Less in children, females before menopause, early morning & in sleep.
        o     Increased in males, greater body build, and day time, after meals, after
             exercise, sleep with dreams.
   · Determinants of Arterial blood pressure:
        Cardiac output; Heart rate; Peripheral resistance; Venous return; Elasticity &
        Diameter of blood vessels; Velocity of blood flow; Viscosity of blood
   · Regulation of Arterial blood pressure:
    o       Nervous mechanism: by vasomotor center & impulse from periphery
    o        Renal mechanism: by regulation of ECF volume & rennin-angiotensin
            mechanism.
    o       Local mechanism
               Local vasoconstrictors & Local vasodilators
    o Hormonal mechanism:
                    Hormones increase BP           Hormones decrease BP
                    Adrenaline                     Vasoactive            intestinal
                    Noradrenaline                  polypeptide(VIP)
                    Thyroxine                      Bradykinin
                    Aldosterone                    Prostaglandin
                    Vasopressin                    Histamine
                    Angiotensin                    Acetylcholine
                    Serotonin                      Atrial natriuretic peptide
· Venous pressure:
              o    Venous pressure in Jugular vein: 5.1 mmHg (6.9 cm H2O)
              o    Venous pressure in superior vena cava: 4.6 mmHg (6.2 cm H 2O)
              o    Portal venous pressure: 10 mm Hg
              o    Hepatic venous pressure: 5 mm Hg.
· Capillary pressure:
        o    Capillary pressure in the arterial end is about 30 – 32 mmHg & venous end is
             about 15 mmHg.
        o     It is high in Kidney (glomerular capillary pressure), about 60 mmHg –
             responsible for filtration.
        o    Low in lungs (pulmonary capillary pressure), about 7 mmHg.


                                                                                         8
· Venous pulse: (it is the pressure changes transmitted in the form of waves from
      right atrium to the veins near the heart)
          o      Recording of JVP is called phlebogram.
          o      Phlebogram has 3 positive waves – a, c & v and 3 negative waves – x, x1 & y.
          o      ‘a’ wave – 1st positive wave & it’s due to atrial systole.
          o      ‘x’ wave – fall of pressure in atrium, coincides with atrial diastole
          o      ‘c’ wave – its due to rise in atrial pressure during isometric contraction during
              which the AV valves bulges into atrium.
          o      ‘x1’ wave – occurs during ejection period, when AV ring is pulled towards
              ventricles causing distension of atria.
          o      ‘v’ wave – occurs during isometric relaxation period or during atrial diastole.
          o      ‘y’ wave – due to opening of AV valve & emptying of blood into ventricle.
Nervous system
  · Neuron is defined as the structural & functional unit of nervous system.
  · Neuron does not have Centrosome so it cannot undergo division.
  · Nissl bodies are organelles containing ribosomes & are concerned with synthesis of
      protein in neurons.
  · Dendrites are conductive in nature & transmit impulses towards the nerve cell body.
  · Axons are longer process of the nerve cell concerned with transmission of impulse
      away from the nerve cell body.
  · The myelin sheath envelops the axon except at its ending and at the nodes of
      Raniver.
  · Myelin sheath is responsible for faster conduction of impulse through the nerve fiber
      & also acts as an insulating material.
  · Neurotrophins are the substances, which facilitate the growth, survival & repair of
      the nerve cells.
  · A alpha (Type Ia) nerve fiber is said to be the fastest nerve with a velocity of
      conduction of 70 to 120 meters / second.
  · Glial cells are very abundant and as many as 10 to 50 times as neurons.
  ·   Astrocytes form supporting network in brain & spinal cord, form basis for blood brain
      barrier.
  ·   Microglia is phagocytic in function.
  ·   Oligodendrocytes are responsible for the formation of myelin sheath in CNS
      because schwann cells are absent there.
  · Receptors:


                                                                                                   9
o    Exteroceptors: give response to stimuli arising from outside the body.
          (Cutaneous, Chemoreceptors & Telereceptors)
      o   Interoceptors: give response to stimuli arising from within the body.
      o   Cutaneous receptors:
      §   Touch receptors: Meissner’s corpuscle & Merkel’s disc (max in lips & fingers)
      §   Pressure receptors: Pacinian corpuscles
      §   Temperature receptor
          o       Cold: Krause’s end organ
          o       Warm: Raffini’s end organ
          o       Warm receptors respond at body temperature of— 30 - 45°C.
          o       Cold receptors are activated at body temperature of— 10°C or below.
          o       Warm Sensation is carried by — C Fibres.
          o       Cold Sensation is carried by — A. & C fibres.
      §    Pain receptors: free (naked) nerve ending. (sensation which return earliest
                     on recovery)
      o   Chemoreceptors:
              §    Taste: Taste buds
              §    Smell: Olfactory receptors
              §    Hearing: hairs cells of organ of corti in the internal ear.
              §    Vision: Rods & Cones in retina – for visual sensation.
      o   Viseroreceptors:
              §    Stretch receptors, baroreceptors, chemoreceptors & Osmoreceptors
      o   Proprioceptors: give response to change in position – labyrinthine, muscle
          spindle, golgi tendon, pacinian
      corpuscle, muscle, tendon & fascia.
· Neurotransmitters:
      o Excitatory neurotransmitter: is responsible for the conduction of impulse from
          the presynaptic neuron to the
      postsynaptic neuron.
      o Inhibitory neurotransmitters: inhibits the conduction of impulse from the
          presynaptic neuron to the postsynaptic neuron.
   Group                Name                            Action
                        GABA                            Inhibitory
   Amino acids          Glycine                         Inhibitory
                        Glutamate                       Excitatory


                                                                                        10
Aspartate                            Excitatory
                    Adrenaline                           Inhibitory & Excitatory
                    Noradrenaline                        Inhibitory & Excitatory
    Amines          Dopamine                             Inhibitory
                    Serotonin                            Inhibitory
                    Histamine                            Excitatory
                    Nitric oxide                         Excitatory
    Others
                    Acetylcholine                        Excitatory
·     Superficial reflexes:
    Reflex         Stimulus                   Response                Center
    Corneal        Irritation of cornea       Blinking of eye         Pons

    Conjunctival   Irritation           of    Blinking of eye         Pons
                   conjuctiva
    Nasal          Irritation of nasal        Sneezing                Motor
                   mucus membrane                                     nucleus of V
                                                                      cranial nerve
    Pharyngeal     Irritation           of    Retching           of   Nuclei   of     X
                   pharyngeal mucus           gagging                 cranial nerve
                   membrane
    Uvular         Irritation of Uvula        Raising of Uvula        Nuclei   of     X
                                                                      cranial nerve
· Superficial cutaneous reflexes
    Reflex          Stimulus                       Response                  Center       –
                                                                             spinal
                                                                             segment
                                                                             involved
                    Irritation of skin at the      Contraction         of
                    interscapular space            scapular muscles &
    Scapular                                                                 C5 to T1
                                                   drawing       in    of
                                                   scapula
                    Stroking                 the   Ipsilateral
    Upper           abdominal wall below           contraction         of
                                                                             T6 to T9
    abdominal       the costal margin              abdominal muscle &
                                                   movement            of


                                                                                              11
umbilicus      towards
                                                         the site of stroke
                          Stroking               the     Ipsilateral
                          abdominal      wall       at   contraction           of
    Lower                 umbilical & iliac level        abdominal muscle &
                                                                                    T10 to T12
    abdominal                                            movement              of
                                                         umbilicus      towards
                                                         the site of stroke
                          Stroking the skin at           Elevation of testicles
    Cremasteric           upper & inner aspect                                      L1, L2
                          of thigh
                          Stroking the skin over         Contraction of glutei      L4 to S1,
    Gluteal
                          glutei                                                    S2
                          Stroking the sole              Plantar     flexion   &
    Plantar                                                                         L5 to S2
                                                         adduction of toes
                          Stroking the dorsum            Contraction           of
    Bulbocavernous                                                                  S3, S4
                          of glans penis                 bulbocavernous
                          Stroking the perianal          Contraction of anal
    Anal                                                                            S4, S5
                          region                         sphincter
·        Deep reflexes
    Reflex                Stimulus                         Response                 Center –
                                                                                    spinal
                                                                                    segment
                                                                                    involved
                          Tapping middle of the            Closure of mouth         Pons – V
    Jaw jerk              chin with slightly opened                                 cranial
                          mouth                                                     nerve
                          Percussion       of   biceps     Flexion of forearm
    Biceps jerk                                                                     C5, C6
                          tendon
                          Percussion     of     triceps    Extension           of
    Triceps jerk                                                                    C6 to C8
                          tendon                           forearm
    Supinator      jerk   Percussion    of      tendon     Supination          &
    or           radial   over distal end (Styloid         flexion of forearm       C7, C8
    periosteal            process) of radius



                                                                                                 12
reflex
       Wrist tendon or          Percussion    of     wrist    Flexion            of
       finger      flexion      tendons                       corresponding           C8, T1
       reflex                                                 finger
       Knee      jerk    or     Percussion   of    patellar   Extension of leg
       Patellar tendon          ligament                                              L2 to L4
       reflex
       Ankle     jerk    or     Percussion   of    Achilles   Plantar flexion of
       Achilles tendon          tendon                        foot                    L5 to S2
       reflex


   Pathological reflexes:
         Babinski’s sign: there is dorsiflexion of great toe & fanning of other toes. Seen in
                UMN lesion, also in infants &
         normal persons with deep sleep.
   Spinal cord:
         Extends from foramen magnum to 1st lumbar vertebra.
         Length – 45 cm in male & 43 cm in females.
         Below the lumbar enlargement, the spinal cord rapidly narrows to a cone shaped
                termination called Conus medullaris.
         Spinal corresponds to 31 pairs of spinal nerves. (C-8; T-12; L-5; S-5; C-1)
         Grey matter is the collection of nerve cell bodies, dendrites & parts of axons.
         White matter is a collection of myelinated & nonmyelinated nerve fibers.
         Neurons in the grey matter of spinal cord
                   Neurons in Anterior gray horn
                        Alpha motor neurons; Gamma motor neurons & Renshaw cells
                   Neurons in lateral gray horn
                        Intermediolateral horn cells
                   Neurons in posterior gray horn
                        Substania gelatinosa of Rolando; Marginal cells; Chief sensory cells &
                              Clarke’s column of cells.
Ascending tracts of Spinal cord:
   Situation            Tract                                  Function
   Anterior white
                        Anterior spinothalamic tract           Crude touch sensation
   funiculus


                                                                                                 13
Lateral spinothalamic tract         Pain & temperature sensation
                                                           Subconscious             kinesthetic
                       Ventral spino cerebellar tract
                                                           sensations
                                                           Subconscious             kinesthetic
                       Dorsal spino cerebellar tract
  Lateral      white                                       sensations

  funiculus            Spinotectal tract                   Concerned with spinovisual reflex

                       Fasiculus dorsolateralis            Pain & temperature sensations
                       Spinoreticular tract                Conciousness & awareness

                       Spinoolivary tract                  Proprioception

                       Spinovestibular tract               Proprioception

                                                           Tactile sensation
                       Fasciculus gracilis
                                                           Tactile localization
  Posterior
                                                           Tactile discrimination
  white
                                                           Vibratory sensation
  funiculus            Fasciculus cuneatus
                                                           Conscious kinesthetic sensation
                                                           stereognosis
Descending tracts of Spinal cord:
   Situation      Tract                        Function
                  Anterior     corticospinal
   Pyramidal      tract                        Control voluntary movements
   tracts         Lateral      corticospinal   Forms upper motor neurons
                  tract
                  Medial        longitudinal   Coordination of reflex ocular movement
                  fasciculus                   Integration of movements of eyes & neck
                  Anterior vestibulospinal     Maintenance of muscle tone & posture
                  tract                        Maintenance of position of head & body
                  Lateral    vestibulospinal   during acceleration
   Extra          tract
                                               Coordination    of     voluntary     &    reflex
   Pyramidal
                                               movements.
   tracts         Reticulospinal tract
                                               Control of muscle tone.
                                               Control of respiration & blood vessels.
                                               Control of movement of head in response to
                  Tectospinal tract
                                               visual & auditory impulses.
                  Rubrospinal tract            Facilitatory influence on flexor muscle tone.


                                                                                                  14
Olivospinal tract              Control of movements due to proprioception.

Effect of upper motor neuron & lower motor neuron lesion:
                         Effects                        upper motor neuron          lower
                                                                                    motor
                                                                                    neuron
                                                                                    lesion
                         Muscle tone                    Hypertonic                  Hypotonic
                         Paralysis                      Spastic type of paralysis   Flaccid type
                                                                                    of paralysis
                         Wastage of muscle              No wastage                  Present
   Clinical
                         Superficial reflexes           Lost                        Lost
   observation
                         Plantar reflex                 Abnormal – babinski’s       Absent
                                                        sign
                         Deep reflexes                  Exaggerated                 Lost
                         Clonus                         Present                     Lost
                         Electrical activity            Normal                      Absent
                         Muscles affected               Groups of muscles are       Individual
                                                        affected                    muscles are
   Clinical
                                                                                    affected
   confirmation
                         Fascicular     twitch     in   Absent                      present
                         EMG
Action of sympathetic & parasympathetic divisions of ANS:
  Effector organ                                 Sympathetic division         Parasympathetic
                                                                              division
  Eye                  Ciliary muscle            Relaxation                   Contraction
                       Pupil                     Dilatation                   Constriction
  Lachrymal secretion                            Decrease                     Increase
                                                 Decrease in secretion &      Increase           in
  Salivary secretion                             vasoconstriction             secretion          &
                                                                              vasoconstriction
                       Motility                  Inhibition                   Acceleration
  GIT                  Secretion                 Decrease                     Increase
                       sphincters                constriction                 Relaxation
  Gall bladder                                   Relaxation                   contraction
  Urinary bladder      Detrusor muscle           Relaxation                   contraction
                       Internal sphincter        Constriction                 Relaxation
  Sweat glands                                   Increase in secretion        -
  Heart rate & force                             Increase                     decrease
  Blood vessels                                  Constriction of all blood    Dilatation


                                                                                                      15
vessels except those in
                                             heart & skeletal muscle
  Bronchioles                                Dilatation                  Constriction
Resting membrane potential of various cells of the body.
   ·Resting membrane potential of a skeletal muscle is -90mV.
   ·Resting membrane potential of a smooth muscle is -50 to -75mV.
   ·Resting membrane potential of a cardiac muscle is -85 to -95mV.
   ·The resting membrane potential in the nerve fiber is -70mV.
   ·The resting membrane potential in the rods is -40mV.
   ·The resting membrane potential of inner ear cell is -60mV.
Brain stem: (medulla oblongata, Pons & Midbrain)
   ·Pathway for ascending & descending tracts b/w brain & spinal cord.
   ·Important centers for regulation of vital functions in body.
   Medulla oblongata
      ·Respiratory centers: inspiratory & expiratory.
      ·Vasomotor center: B.P & Heart rate.
      ·Deglutition center: Pharyngeal & Oesophageal stage.
      ·Vomiting center: induce vomiting.
      ·Superior & inferior salivatory nuclei: controls secretion of saliva.
      ·Cranial nerve nuclei: nuclei of 10, 11 & 12 cranial nerves.
      ·Vestibular nuclei:
   Pons
      ·Bridge b/w medulla & midbrain.
      ·Forms pathway connecting cerebellum with cortex.
      ·Nuclei of 5 to 8th cranial nerve.
      ·Pneumotoxic & apneustic centers for regulation of respiration.
  Midbrain: (Consist of 2 parts Tectum & cerebral peduncles)
   ·Tectum: center for light & auditory reflexes.
   ·Cerebral peduncles: control of muscle tone
   ·Control of complex & skilled muscular movements, movement of eye balls
  Thalamus: Ovoid mass of gray matter, situated B/L in diencephalons)
       ·Relay center: for sensations (also called functional gateway).
       ·Center   for   integration   of    sensory   impulses:   determining   the      quality   of
          sensations(discriminative & affective nature)
       ·Center for sexual sensations.


                                                                                                  16
·Role in arousal & alertness reactions.
       ·Center for reflex activity
       ·Center for integration of motor functions.
 Hypothalamus:
·Control the secretion of Ant. & Post Pituitary hormones & adrenal cortex & medulla.
·Control of Autonomic nervous system; Heart rate; B.P; Body temp; Food intake
   (satiety, hunger &thirst); water balance; sleep & wakefulness.
·Role in behaviour & emotional changes.
·Regulation of sexual function & response to smell.
·Role in circadian rhythm.
 Cerebellum:
·Vestibulocerebellum: regulates tone, posture & receiving impulse for vestibular
   apparatus.
·Spinoncerebellum: regulates tone, posture & equilibrium by receiving impulses from
   proprioceptors in muscles, tendons
& joints, tactile receptors, visual receptors & auditory receptors.
· Corticocerebellum: concerned with the integration & regulation of well coordinated
   muscular activities.
·Different parts are represented in an upright manner in cerebellum. (opp: in cerebrum)
 Basal ganglia: (concerned with motor activities of extra-pyramidal system)
·Control of voluntary motor activity, muscle tone, reflex muscular activity, associated
   movements.
·Role in arousal mechanism.
 Cerebral cortex:
                            Primary motor area          Area 4 – center for movement
                            (concerned           with
                            initiation of voluntary     Area 4S – suppressor area.
               Pre                                      Inhibits movements initiated by
                            movements & speech)         area 4.
               central
Frontal        cortex                                   Area 6 – concerned with
                                                        coordination     of  movements
lobe           (Post.                                   initiated by area 4.
                            Pre motor area
               Part)                                    Area 8 – frontal eye field.
                                                        Area 44 & 45(broca’s area) –
                                                        motor area for speech.
                            Supplementary               Concerned with co-ordinated
                            motor area                  skilled movements.
               Pre      –   Silent   area         or    Area – 9 to 14, 23, 24, 29 &



                                                                                          17
frontal    association area          32. Center for planned action.
               cortex     Center     for higher     Seat of intelligence. Personality
                          functions – emotion,      of individual.
               (Ant.
                          learning, memory.
               Part)
                                                    Area      1   –    concerned   with
                                                    sensory perception

               Somesthetic area I                   Area 2 & 3 – integration of
                                                    these      sensations.       Spatial
  Parietal                                          recognition.     Recognition      of
                                                    intensity, similarities & diff. B/W
  lobe
                                                    stimuli
                                                    Concerned with perception of
               Somesthetic area II
                                                    sensation.
                                                    Synthesis of various sensations
               Somesthetic association area         perceived        by       S.Area-I.
                                                    Stereognosis.
               Primary auditory area                Area 41, 42 & wernicke’s
                                                    area      –       concerned    with
                                                    perception of auditory impulses,
  Temporal
                                                    analysis of pitch, determination
  lobe
                                                    of intensity & source of sound
               Auditopsychic area                   Area 22 – interpretation of
                                                    auditory sensation
               Area of equilibrium                  Maintenance of equilibrium
               Primary visual area                  Area 17 – perception of visual
                                                    impulse
  Occipital
               Visual association area              Area   18     -   Interpretation   of
  lobe
                                                    visual impulses
               Occipital eye field                  Area 19 - Movements of eye


Limbic system: (It is a group of cortical & sub cortical structures which form a ring around
  the hilus of cerebral hemisphere)
   ·Regulation of olfaction, autonomic functions (B.P, water balance & body temp).
   ·Control of circadian rhythm.
   ·Regulation of sexual function.
   ·Role in emotional state, memory & motivation.
   ·Retention of recent memory.
   ·Most developed part of Limbic System — Hippocampal formation
   ·Major efferent from Limbic system goes to — Mid brain reticular formation.
   ·Main function of Limbic system is to — Control the emotional behaviour.

                                                                                            18
Proprioceptors: (These are receptors which give response to change in the position of
different parts of the body).
   ·Muscle spindle: gives response to change in length of muscle.
   ·Golgi tendon organ: gives response to change in force developed in muscle.
   ·Pacinian corpuscle: pressure receptor in fascia, tendon & joints.
   ·Free nerve endings:
Vestibular apparatus:
   ·Give response to rotatory movements or angular acceleration of the head.
   ·Responsible for detecting the position of head during different movements.
EEG: (ELECTROENCEPHOLEGRAM)
   ·Alpha rhythm:
          Frequency: 8 to 12 waves / sec
          Amplitude: 50µU.
          Most marked in parieto-occipital area.
          Obtained in inattentive brain as in drowsiness & light sleep.
   ·Beta rhythm:
          Frequency: 15 to 60 waves / sec
          Amplitude: 5 - 10µU.
          Recorded during mental activity or mental tension or arousal state.
   ·Delta rhythm:
          Frequency: 1 to 5 waves / sec
          Amplitude: 20 - 200µU.
          Seen in tumour, epilepsy, increased intracranial pressure & mental depression.
   ·Theta rhythm:
          Frequency: 4 to 8 waves / sec
          Amplitude: 10µU.
          Seen in children below 5 years.
SLEEP:
   ·Sleep requirement:
          Newborn infants: 18 to 20 hours.
          Growing children: 12 to 14 hours.
          Adults: 7 to 9 hours.
          Old persons: 5 to 7 hours.
   ·Types of sleep:
        Rapid eye movement sleep(REM)       Non    rapid    eye     movement
                                            sleep(NREM)

                                                                                           19
Eye balls move                         Absent
    Dreams occur                           Absent
    Muscle twitching                       Absent
    20 to 30% of sleep                     70 to 80% of sleep
·Normal amount of C.S.F. in man is 150 C.C,
·Sympathetic nervous system is controlled by — Posterior hypothalamic nuclei
·Parasympathetic nervous system is controlled by — Anterior nuclei and part of middle
   nuclei of hypothalamus.
EYE:
§Refractory power is measured in dioptre (D).
§Refractory power of cornea is 42D.
§Refractory power of lens is 23D.
§Refractory power of eye at rest is 59D.
§Focal length of cornea is 24mm.
§Focal length of lens is 44mm.
§The wave lengths of visible light are approximately 397 to 723 nm.
§There are about 6 million cones & 12 million rods in human eye.
§Rods are responsible for dim light or night vision or scotopic vision.
§Cones are responsible for colour vision, sensitive to day light & acuity of vision.
§Rhodopsin is the photosensitive pigment of rods cells.
§Photosensitive pigment in cones are
       o Porpyropsin – Red
       o Iodopsin – Green
       o Cyanopsin – Blue
§ Electroretinogram is the instrument to record the electrical basis of visual process.
§ Test for visual acuity – snell’s chart (distant vision) & Jaeger’s chart (near vision).
§ Test for color blindness – Ishihara’s colour chart.
§ Mapping of visual field – perimetry.
§ Nearest point at which the object is seen clearly is about 7 to 40cm.
§ Farthest point is infinite.
§ Myopia (short sightedness) is corrected by concave lens.
§ Hypermetropia (long sightedness) is corrected by convex lens.
§ Astigmatism is corrected by cylindrical lens.
§ Presbyopia is corrected by convex lens.
EAR:


                                                                                            20
§   Ear is sensitive to sound between 1000 to 4000Hz range.
  §   Hairs cells in organ of corti are the receptors for auditory sensation.
  §   Sound becomes painful above 140db.
  §   Auditory centers – 41, 42 & also auditopsychic area 22.
  TONGUE:
  §   Sense organ of taste sensation is taste buds.
  §   There are about 10,000 taste buds & each taste bud is replaced in every 10 days.
  §   Each taste bud consists of 4 types of cells and is supplied by about 50 nerve fibres.
  §   Receptors are type III cells of taste buds.
  §   Taste center – opercular insular cortex (lower part of post central gyrus).
  §   Bitter taste has very low threshold – 1 in 2,000,000.
  §   Sweet taste has high threshold – 1 in 200.
  §   Locations of taste buds are: sweet – tip; salt – dorsum; sour – side; bitter –
      posterior.
  SMELL:
  §   Olfactory mucus consists of 10 to 20 million olfactory receptor cells.
  §   Human nose can distinguish 2000 to 4000 different odours.


GASTRO INTESTINAL SYSTEM
     GIT is a tubular structures extending from the mouth up to anus with a length of
      about 30 feet.
     A normal healthy adult consumes about 1kg solid diet & about 1 – 2 liters of liquid
      diet / day.
     Auerbach’s plexus regulate the movements of GIT.
     Meissner’s plexus regulate the secretory functions of GIT.
     Auerbach’s plexus is present between the middle circular muscle layer & outer
      longitudinal muscle layer & its major function is to regulate the movements of GIT.
     The total volume of GIT secretions per day is about 8000 ml.
     Properties & composition of Saliva:
         ·          Volume: 1000 – 1500 ml / day, (70% by submaxillary glands).
         ·          Reaction: pH 6.35 – 6.85.
         ·          Specific gravity: 1.0002 – 1.012
         ·          Composition: 99.5% water & 0.5% solids.
         ·          Digestive enzymes: salivary amylase (carbohydrate splitting) & lingual
             lipase (lipid splitting enzyme).



                                                                                              21
·      Substances like mercury, potassium iodide, lead & thiocyanate are excreted
    through saliva.
·      Saliva contains highest conc. of K+.
·      Volume of stomach is 50 ml when empty & can expand up to 4 liters.
·      Properties & composition of gastric juice:
       ·      Volume: 1200 – 1500 ml / day.
       ·      Reaction: pH 0.9 – 1.2.
       ·      Specific gravity: 1.002 – 1.004
       ·      Composition: 99.5% water & 0.5% solids.
       ·      Digestive enzymes: Pepsin, Gastric lipase & other gastric enzymes.
·      Action of pepsin: attacks peptide bonds adjacent to aromatic amino acids by
    hydrolysis.
·      Action of gastric lipase: weak lipolytic enzyme becomes active only when pH is
    between 4 & 5.
·      Action of HCL: activates pepsinogen into pepsin, bacteriolytic action, causes
    acidity of the chime & provides acid medium for the action of enzyme.
·      Gastrin is one of the GIT hormones secreted by G cells present in pyloric glands
    of stomach.
·      Action of Gastrin: stimulates the secretion of pepsinogen & Hcl by gastric glands,
    increases the motility of stomach, secretion of pancreatic juice & production of
    hormones by pancreas.
·      Pancreas is a dual organ & has endocrine & exocrine function.
·      Properties & composition of Pancreatic Juice:
       ·      Volume: 500 – 800 ml / day.
       ·      Reaction: pH 8 – 8.3.
       ·      Specific gravity: 1.010 – 1.018
       ·      Composition: 99.5% water & 0.5% solids.
       ·      An adult pancreas has 2.5-7.5 lac islets.
       ·      Total volume of pancreatic secretion per day is 2.5 liters.
       ·      Pancreas is the only organ that contains Trypsinogen.
       ·      Ascariasis can also cause acute pancreatitis.
       ·       Serum amylase and lipase levels are usually not elevated in chronic
           pancreatitis.
·     Duodenum is the principal site of iron absorption.




                                                                                       22
·       Most sensitive method for assessing pancreatic exocrine function is Secretin
    Stimulation Test.
   Blood flow reaching the liver via portal versus hepatic artery is 4: 1.
   Hepatic venous pressure is 5 mm Hg.
   Most common complaints resulting from disorders involving the GIT include pain and
    alteration in bowel habit.
   Most potent stimulus for bile secretion is bile salt.
   Best stimulus for CCK secretion is Fat.
   Properties of Bile:
        o   Volume: 800 – 1200 ml / day
        o   Reaction: alkaline
        o   pH: 8 – 8.6
        o   Sp. Gty: 1010 - 1011
   Composition of Bile:
        o   Water: 97.6%
        o   Solids: 2.4%
   Bile is stored in gall bladder; it undergoes many changes in quality & quantity.
   There is increase in conc. of bile salts, bile pigments, cholesterol, fatty acids &
    lecithin.
   Functions of bile salts:
        o   Emulsification of fats, due to emulsification, fat globules are broken down into
            minute particles.
        o   Absorption of fats.
        o   Stimulate the secretion of bile from liver.
        o   Prevention of gall stone formation.
   Properties of succus entericus:
        o   Volume: 1800 ml / day
        o   Reaction: alkaline
        o   pH: 8 – 8.3
        o   Sp. Gty: 1010 - 1011
   Enzymes of succus entericus:
        o   Proteolytic     enzymes:   peptidases   –     amino   peptidases,   dipeptidase   &
            tripeptidase.
        o   Amylolytic enzymes: sucrase, maltase, isomaltase, lactase, dextrase &
            trehalase.


                                                                                              23
o   Lipase & enterokinase
     Bacterial flora of large intestine synthesizes folic acid, Vit B12 & Vit K.
     Vomiting center is situated bilaterally in medulla oblongata near the nucleus
      tractus solitarius.
     Segmentation contraction & pendular movement are involved in mixing of food in
      small intestine.
     Peristaltic movements peristaltic rush are the two movements involved in the
      pushing of chyme towards aboral end on intestine.
     Desire for defecation is elicited by an increase in the intrarectal pressure to about
      20 to 25 cm H2O.
     Gastrointestinal hormones:
       Hormone              Source            of   Actions
                            secretion
       Gastrin              G       cells     of   1. Stimulates the secretion of gastric
                            stomach;               juice.
                            duodenum,              2. Increase the gastric motility.
                            jejunum, Ant. Pit &    Stimulates the release of pancreatic
                            Brain                  hormones.
       Secretin             S       cells     of   Stimulates       secretion       of    watery,
                            duodenum,              alkaline & pancreatic secretions.
                            jejunum & ileum
       Cholecytokinin       I       cells     in   Stimulates contraction of gall bladder;
                            duodenum,              Activates     secretin;     Inhibits      gastric
                            jejunum & ileum        motility;      Increases        secretion     of
                                                   enterokinase & intestinal motility.
       Gastric              K       cells     in   Inhibits    secretion      of   gastric    juice,
       inhibitory           duodenum          &    gastric     motility   &    increase      insulin
       peptide (GIP)        jejunum                secretion.
     Digestion of Carbohydrates:
    Area         Juice          Enzyme              Substrate              End Product
    Mouth        Saliva         Salivary amylase    Polysaccharides        Disaccharides
                 Gastric        Gastric amylase     Weak amylase           The       action        is
    Stomach
                 juice                                                     negligible
    Small        Pancreatic     Pancreatic          Polysaccharides        Disaccharides           –



                                                                                                        24
intestine    juice        amylase              Disaccharides      dextrins, maltose &
                                                                        maltriose
                                                                        Monosaccharides
                   Succus       Sucrase              Disaccharides      Glucose
                   entericus    Maltase
                                Lactase
                                Dextrinase
                                Trehalase
Skin
       Skin is the largest organ in the human body.
       The normal body temperature varies is between 35.8 – 37.30.
       Axillary temperature is slightly lower, while rectal temp. is slightly higher.
       Heat lose center is situated in pre-optic nucleus of ant. Hypo thalamus.
       Heat gain center is situated in post. Hypothalamic nucleus.
       Primary motor center for shivering is situated in post. Hypothalamus, near the wall
        3rd ventricle.


RESPIRATORY SYSTEM
       The major phospholipids present in the surfactant are di-palmitoylphosphatidyl
        choline.
       Surfactant is secreted by type II alveolar epithelial cells.
       Total peripheral resistance falls about 50% in moderate exercise.
       Cyanosis      is    detectable   when   arterial   oxygen    saturation   falls   below   75%
        corresponding to PO2 of 40 mmHg.
       250ml of oxygen enters the body per min and 200 ml of CO2 is excreted.
       5 ml of 02 is transported to the tissues by 100 ml blood in every cycle
       Pulmonary alveolar macrophages form called "Dust cells".
       Size and strength of respiratory muscles is 30-40% above normal in athletes
        whereas it is 20-30% less in physically weak people.
       There are about 300 million alveoli in man.
       There is no stimulation of ventilation by hypoxia until the alveolar O2 falls below 60
        mm Hg.
       Oxygen transported from lung to tissues in chemical combination is 97%.
       In a healthy adult, 24 hour production of CO2 is about 330 liters.
       Diffusion capacity for carbon dioxide as compared to that of 02 is 20 times.


                                                                                                   25
   Average area of the alveolar walls in contact with capillaries in both lungs is about
    70 sq. m.
   Diffusion capacity of lungs for CO2 is 10-30 ml/min/mmHg.
   Normal composition of venous blood is PO 2 - 40 mmHg, PCO2 -46 mm Hg and Hb
    saturation 75%.
   Peak expiratory flow rate is 400-500 L/mt.
   The presence of Hb increases the 02 carrying capacity of the blood by 70 fold.
   Intra-pleural pressure (recoil pressure) required to prevent collapse of the lung —
    4 mm Hg in presence of surfactant.
   Intrapleural pressure at the end of deep inspiration is - 4 mm Hg.
   Intrapleural pressure during expiration is - 2 mm Hg.
   Compliance of the normal lungs and thorax combined — 0.13 liter/cm, of H2O.
   Compliance of the normal lungs alone is 0.22 liter/cm of H2O.
   During normal quiet breathing only 2-3% of the total energy expenditure is needed
    for pulmonary ventilation.
   The amount of alveolar air replaced by new atmospheric air with each breath is only
    l/7th.
   Expired air contains 2/3rd alveolar air + l/3rd dead space air.
   63% of carbon dioxide is transported as bicarbonate form
   97% of O2 is transported by Hb, rest 3% is in dissolved state in the water of the
    plasma and cells.
   Carbon mono oxide binds with Hb. 230 times more strongly than ()2.
   Under resting conditions each 100 ml of blood transports 5 ml of O2 to tissues and
    carries 4 ml of CO2 from tissues to the lungs.
   Death occurs usually when the pH of the blood falls to 6.9.
   The decrease in 02 affinity of Hb when the pH of blood falls is called Bohr’s effect.
   The degree of stimulation of chemoreceptors depends on arterial PO2.
   Spirometer cannot measure Functional Residual Capacity.
   Functional residual capacity is measured by Nitrogen wash out or single breath
    oxygen method.
   Most potent respiratory stimulant is carbon dioxide.
   Kausmaul breathing is seen in diabetic ketoacidosis and it is not a feature of
    Hypercapnic acidosis.
   Hering-breuer reflex: impulses from stretch receptors.
   Peripheral chemoreceptors are carotid & aortic bodies.


                                                                                        26
   Respiratory centers:
         o   Inspiration – dorsal group of neurons near tractus solitarius nucleus.
         o   Expiration – ventral group situated in ventral part of medulla.
     Normal value of FEV 1 in an adult male is 80%.
     Muscles of Inspiration — Diaphragm and External Intercostals muscle (Others -
      Stcrnocleidomastoid, Serratus anterior).
     Muscle of Expiration —Internal Intercostal muscle. (Rectus abdominis).
     Intra alveolar pressure during inspiration — 1 mm Hg.
     Tidal volume: 500 ml.
     Inspiratory reserve volume: 3300 ml.
     Expiratory reserve volume: 1000 ml.
     Residual volume: 1200 ml.
     Respiratory minute Volume in a normal person is 6.0 L/min.
     Inspiratory capacity: 3800 ml.
     Vital capacity : 4800 ml.
     Total lung capacity: 6000 ml.
     Functional residual capacity in a male is 2.2 liters.
     Normal dead space air volume — 150 ml.
     Timed vital capacity in 1sec is 83%.
     Timed vital capacity in 2 sec is 94%.
     Oxygen dissociation curve is ‘S’ shape or sigmoid shape.
       Shift to right                   Shift to left
       Decrease pH                      Increase pH
       Increase in temp                 decrease in temp
       Excess of 2, 3 DPG               Foetal blood
       Increase PCO2 (Bohr effect)      -
       Decrease PO2                     -


ENDOCRINE SYSTEM
     Hormone which acts on the target cell is called as 1st messenger.
     Cyclic AMP is the most common 2nd messenger for protein hormones.
     Other 2nd messengers are Ca++, Calmoduline, Inositol triphosphate(IP3) & cyclic
      GMP.
     Anterior pituitary hormones are
         o   Growth hormone or somatotropic hormone


                                                                                      27
o      Thyroid stimulating hormone
       o      Adenocorticotropic hormone
       o      Follicle stimulating hormone
       o      Luiteinizing Hormone or interstitial cell stimulating hormones in males
       o      Prolactin.
   Posterior pituitary hormones are
       o      Antidiuretic hormone or vasopressin
       o      Oxytocin
   ADH causes conservation of body water & contraction of vascular smooth muscle.
   Gigantism is due to the hyper secretion of growth hormone in childhood or in the
    pre-adult life before the fusion of epiphysis of bone with the shaft.
   Acromegaly is due to hyper secretion of GH in adults after the fusion of epiphysis
    with shaft of the bone.
   Dwarfism is a disorder of GH reduction in infancy or early childhood.
   Diabetes insipidus is a syndrome developed due the defiency of ADH.
   Hormone responsible for uterine contraction during labour & letting down of milk is
    Oxytocin.
   The anterior pituitary has the largest blood flow of any tissue in the body.
   Anterior pituitary hormones with diabetogenic effect – GH, ACTH, TSH, and PRL.
   Pigmentation is not a feature of panhypopituitarism.
   Hormones of thyroid gland are
       o      Thyroxine (T4) – 90%
       o      Triiodothyronine (T3) – 10%
       o      Calcitonin
   Potency of T3 is four times more than that of T4.
   Graves’         disease     is     an    auto-immune        disease     which       causes
    hyperthyroidism.(exophathalmic goiter)
   Cretinism is hypothyroidism in children & myxedema due to hypothyroidism in
    adults.
   Parathormone is secreted by para thyroid gland & its main function is to increase
    the blood Ca++ level by mobilizing Ca++ from bone.
   Calcitonin reduces the blood Ca++ level by decreasing the bone re-absorption.
   Tetany results from hypocalcaemia, caused by hypoparathyroidism.
   Pancreatic hormones are
       o      Alpha cell – Glucagons


                                                                                            28
o   Beta cells – Insulin
       o   Delta cells – Somatostatin
       o   F or PP cells – Pancreatic polypeptide
   Insulin is the only anti diabetic hormone secreted in the body.
   Glucagons actions are antagonistic to that of insulin.
   Somatostatin inhibits the secretion of both glucagons & Insulin.
   Hormones of Adrenal cortex are
       o   Mineralocorticoids (secreted by zona glomerulosa)
                  Aldosterone (↑ Na+ & excretion of K+)
                  11 deoxy corticosterone
       o   Glucocorticoids (zona fasiculata)
                  Cortisol
                  Corticosterone
       o   Sex hormones (zona reticularis)
                  Dehydroepiandrosterone
                  Androstenedione
                  Testosterone




   Cushing syndrome is a disorder characterized by obesity due to hyper secretion of
    glucocorticoids.
   Conn’s syndrome is primary aldosteronism.
   Addison’s disease is chronic adrenal insuffiency.
   Hormones of Adrenal medulla (Catecholamines) are
       o   Adrenaline or epinephrine
       o   Noradrenaline or norepinephrine
       o   Dopamine
   Pheochromocytoma is a condition in which there is excessive secretion of
    catecholamines.
   Melatonin is secreted by parachymal cells of pineal gland, acts on gonads.
   Severe stress can raise ACTH and cortisol level by 20 folds.
   Fetal lung maturation depends on increased fetal Cortisol just before birth.
   Human prolactin causes synthesis of milk in the female breast.
   The half life of circulating growth hormone in humans is 20 to 30 minutes.




                                                                                   29
BLOOD
   Blood is a connective tissue in fluid form.
   Blood is 5 times viscous than water.
   Blood cell count is greater in children than adult.
   RBC is microcytic in iron defiency anaemia, prolonged forced breathing &
    increased osmotic pressure.
   RBC is macrocytic in megaloblastic anaemia, muscular exercise & decreased
    osmotic pressure in blood.
   Punctate basophlism is seen in lead poisoning.
   Goblet ring is seen in certain types of anaemia like malaria.
   Red cell vol. can be determined by radio isotope 51 Cr.
   Cyanosis appears when the reduced Hb cone, of the blood in the capillaries is more
    than 5 gm/dl.
   In vitro, coagulation is initiated by factor XII.
   Life of RBC's in adult human body is 120 days.
   Average life span of RBC in a newborn is 100 days.
   Average life span of RBC in transfused blood is 90 days.
   Life span of transfused platelets is 4 days.
   Life span of platelets is 9-12 days.
   Complete erythropoiesis occurs in 7 days.
   Erythropoiesis occurs in
       o   In first trimester RBC's are formed in Yolk sac. While in second trimester
           liver is the main organ. Third trimester in liver & bone marrow.
       o   Upto age of 5 – 6 yrs – red bone marrow of all bones.
       o   6 – 20 yrs – red bone marrow of all bones & all membranous bones.
       o   After 20 yrs – all membranous bones & ends of long bone.
   Hb starts appearing in intermediate normoblastic stage of erythropoiesis.
   Nucleus disappears during late normoblastic stage.
   Factors needed for Erythropoiesis: erythropoietin, thyroxine, interleukins 3, 6, 11,
    stem cell factors, Vit B, C & D. (maturation factors Vit B12 & folic acid).
   The iron remains in ferrous state.
   The affinity of Hb for CO2 is 20 times more than for O2.
   The affinity of Hb for CO is 200 times more than its affinity for O2.
   Adult Hb consists of 2 alpha & 2 beta chains.
   Fetal Hb consist of 2 alpha & 2 gamma chains.


                                                                                     30
   In sickle cell anemia, the 2 alpha chains are normal but 2 beta chains are
    abnormal.
   In Hb C, beta chains are abnormal.
   Bilirubin is the final product formed from the destruction of Hb.
   Total quantity of the iron in the body is 4gm.
   1 mg of iron is excreted every day through faeces.
   Normocytic normochromic anaemia is seen in aplastic aneamia.
   Marcocytic    normochromic           anaemia     seen   in   folate   deficiency,    Vit   B12   &
    hypothyroidism.
   Pernicious anaemia or addsion's anaemia is marcocytic normochromic anaemia.
   Microcytic     hypochromic           is   seen     in    iron     deficiency,       thalassemia,
    heamoglobinopathies & heamolytic anaemia.
   ESR decreases         in allergic conditions, sickle cell        anaemia, polycythemia &
    afibrinogenemia.
                   Character                             Normal
     1.     ESR                          Male: 3 – 7 mm / hr
                                         Female: 5 – 9 mm / hr
     2.     PCV     (Packed       cell   Male: 40 – 45 %
            volume)                      Female: 38 – 42 %
            (Hematocrit)
     3.     MCV                (Mean     90 cuµ (78 – 90 cuµ)
            corpuscular volume)
     4.     MCH                (Mean     30 pg (27 – 32pg)
            corpuscular Hb)
     5.     MCHC               (Mean     30% (13 – 38%)
            corpuscular Hb Conc.)
     6.     Colour index                 1 (0.8 – 1.2)
     7.     WBC                          4000 – 11,000 / cmm
     8.     D.C
            Neutrophils                  50 – 70%
            Eosinophils                  2–4%
            Basophils                    0–1%
            Monocytes                    2 – 6%
            Lymphocytes                  20 – 30 %



                                                                                                     31
9.     Platelet count              2,50,000( 2 lakhs – 4 lakhs)
     10.    Bleeding time               3 – 6 min
     11.    Clotting time               3 – 8 min
     12.    Prothrombin time            12 sec
     13.    Activated         partial   25 – 40 sec
            thromboplastin
            time(APTT)
     14.    RBC                         4 – 5.5 millions / mm3
            Adult male                  5 millions / mm3
            Adult female                4.5 millions / mm3
            Birth                       8 – 10 millions / mm3


     15.    Heamoglobin
            Adult male                  14 – 18 gm / dl
            Adult female                12 – 16 gm / dl
            New born                    16 – 22 gm /dl
     16.    RBC
            Diameter                    7.5 µ
     17.    Blood volume                5 liters
   Granulocytes are neutrophils, eosinophils & basophils.
   Agranulocytes are monocytes & lymphocytes.
   Monocyte is the largest lymphocyte.
   In hemophilia clotting time is prolonged in presence of normal bleeding time.
   Christmas disease occurs due to deficiency of factor IX.
   Clotting factors
     Factor I       Fibrinogen
     Factor II      Prothrombin
     Factor III     Thromboplastin
     Factor IV      Calcium
     Factor V       Pro accelerin (labile factor)
     Factor VI      No such factor
     Factor VII     Stable factor
     Factor VIII    Anti hemophilic
     Factor IX      Christmas


                                                                                    32
Factor X          Stuart-power
     Factor XI         Plasma thrombplastin antecedent
     Factor XII        Hegman (Conduct)
     Factor XIII       Fibrin stabilizing factor (Fibrinase)
   Blood group:
     Group         Antigen in RBC                 Antibody in serum
     A             A                              Anti – B (β)
     B             B                              Anti – α
     AB            A&B                            No anti body
     O             No antigen                     Anti A & Anti B
   Universal recipient are Blood Group 'AB because it does not contain either Anti A
    ab or anti B ab.
   Universal donor is Blood Group "()" because it docs not contain either A or B
    agglutinogen (antigen).
   Commonest blood group is O.
   Diseases associated with blood groups:
         o   Group A – C.A stomach
         o   Group O – duodenal ulcer
   Normal basic acid output is 5-10 mmol/hour.
   Blood is stored in the blood bank at 40C.
   The number of iron Heme in one Hb molecule is 4.
   The number of O2 molecules carried by one Hb molecule is 4.
   Mean corpuscular diameter is 7.5 nm.
   Maximum concentration of Hb normally found in RBC's is 34%.
   In arterial blood, saturated Hb with 02 is 97%.
   Thromboxane A2 is synthesized by platelets and promotes vasoconstriction and
    platelet aggregation.
   In sickle cell anemia, valine is substituted for glutamic acid.
   Platelets are derived from megakaryocytes.
   Pus contains — Dead neutrophils, macrophages and necrotic tissues.
   Cardiac output in anemia is above normal while in polycythemia is about normal.
   Agglutinins are either IgM or IgG.
   In Erythroblastosis fetalis, mother is Rh-, father is Rh+, foetus is Rh positive.
   Hapatoglobin is a plasma protein responsible for carrying free Haemoglobin.
   Usual anticoagulant used for transfusion is a citrate salt.

                                                                                        33
   Earliest feature of iron deficiency anemia is decreased serum ferritin.
   Arneth count is used in the determination of the percentage distribution of different
    types of neutrophils on the basis of no: nuclear lobes.
   Wilson’s disease is due to decrease in caeruloplasmin.


                                 EXCRETORY SYSTEM
   Hormones secreted by kidney are erythropoietin, thrombopoitein, renin & 1, 25
    dihydroxy cholecalciferol.
   1 kidney contains about 1 – 1.3 millions nephrons.
   Ratio of corical nephrons to Juxtamedullary nephrons 85: 15.
   The GFR of average sized normal man is approximately 125 ml / minute or 180
    liters / day.
   At the rate of 125 ml/min, the kidneys filter an amount of fluid equal to 4 times the
    TBV, 15 times the ECF vol. and 60 times the plasma volume.
   1 – 1.5 liters of urine formed / day.
   Urine osmolality in diabetes insipidus is 300 mmol/L.
   Normal protein excretion is 50 -150 mg%.
   The quantity of water lost as sweat per day is 600-800 C.C
   Normal urea clearance is 44 ml/min.
   Renal blood flow is 25% of cardiac output (1300 ml blood/min).
   Total length of distal convoluted tubule is 5 mm.
   Glomerulus membrane permits the passage of substances upto 4 nm and almost
    totally excludes substance with size greater than 8 nm.
   Each glomerulus is a net work of approximately 50 parallel capillaries.
   Urinary osmolality in diabetes insipidus is 300 m mol/Lit.
   Glucose and amino acid are absorbed in proximal convoluted tubules by secondary
    active transport or sodium Co-transport.
   Descending limb of thin segment of loop of Henle is freely permeable to
    water.
   Areas impermeable to water — ascending limb of thin segment thick segment of
    loop of Henle. Proximal half of convoluted tubule.
   Areas impermeable to urea — Distal convoluted tubule & cortical portion of
    collecting tubules.
   Substances completely reabsorbed in PCT — Glucose, proteins, amino acids,
    vitamins, acetoacetate.


                                                                                      34
   Substances partially absorbed in PCT—Na. K, Cl (7/8 reabsorbed in PCT).
   Substances secreted in PCT — H+, PAH (para amino hippurate). creatinine.
   H+ are actively secreted in proximal tubules, distal tubules, collecting ducts.
   Hyperosmilality in the interstitum is the prerequisite for excretion of concentrated
    urine.
   Urea is reabsorbed from inner meduallary collecting ducts only in presence of ADH.
   K+ is actively secreted in Late Distal tubules and Collecting ducts.
   Macula densa is the epithelial cells of the distal tubule that comes to contact with
    the arterioles.
   Juxtaglomerular cells produce renin.
   Renin acts on angiotensinogen & convert it into angiotensin I.
   Renal threshold for glucose is reduced in renal glycosuria.
   Creatinine clearance represents GFR.
   Clearance test for renal function includes inulin clearance, creatinine clearance &
    PAHA test.
   PAHA test is performed to assess renal blood flow.
   Micturition is primarily a spinal reflex.
   Thick ascending loop of henle is impermeable to water.
   Majority of sodium absorption occur in the proximal tubule.
              Character                                 Normal
     pH                               4. 5 – 6
     Volume                           1000 – 1500 ml / day
     Specific gravity                 1.010 – 1.025


                            MALE REPRODUCTIVE SYSTEM
   Average pH of semen is 7.5.
   Life span of spermatozoa within the female genital tract is upto 24 hours.
   Speed of human sperm in female genital tract is about 3 mm/min.
   Male sex hormones          are called       the androgens (secreted   by   leydig   cells);
    testosterone, dihydro testosterone & androstenedione.
   Mullerian ducts gives rise to female accessory sex organs such as vagina, uterus &
    fallopian tube.
   Wolffian duct gives rise to male accessory sex organs such as epididymis, vas
    deferens & seminal vesicles.




                                                                                            35
   Fetal testes begin to secrete the testosterone at about 2 nd to 4th month of
    embryonic life.
   The    secretion       from   seminal   vesicles   contains   fructose,    phophorylcholine,
    fibrinogen, ascorbic acid, citric acid, pepsinogen, acid phosphatase & prostaglandin.
   Fructose & citrate acts as fuel for the spermatozoa.
   Prostatic secretion is rich in enzymes, fructose & citrate.
   Androgen appears to be essential for spermatogenesis. Whereas FSH is required for
    spermatic maturation.
   Testes do not produce fructose.(seminal vesicle)
   Sertoli cells provide nutrition to the developing sperm; secrete oestrogen &
    hormone binding proteins.
   Testosterone is synthesized from pregnanolone.
   Testosterone stimulates the process of spermatogenesis, also necessary for the
    formation of secondary spermatocyte from primary spermatocyte.
   Growth hormone is essential for the general metabolic processes in testis.
   Male sex hormone is secreted mainly by interstitial cells of Leydig.
   Development of male sex organ in fetal life depends on testosterone produced
    under the influence of HCG.
   Testosterone circulates in Combination with Gonadal steroid binding globulin.
   Hormone used for treating osteoporosis in old age — Testosterone.
   In    males      FSH   promotes   spermatogenesis    by   enhancing       the   transport   of
    Testosterone to seminiferous tubules and androgen binding protein synthesis from
    sertoli cells.


                             FEMALE REPRODUCTIVE SYSTEM
   During menstrual period, upto 20 gm of protein may be lost.
   Quantity of blood expelled during normal menstral cycle is 40 ml (approx) & serous –
    35 mls.
   FSH level is high in post menopausal women.
   Ovarian hormones are estrogen and progesterone
   Ovulation occurs on the 14th day of menstrual cycle in a normal cycle of 28 days.
   Oxytocin causes contraction of smooth muscles of uterus & enhances labour.
   Hormones secreted are HCG, Oestrogen, progesterone & human chorionic somato
    mammo tropin.




                                                                                                36
   Relaxin is a hormone secreted from the maternal ovary during the later periods of
    pregnancy.
   Biological test for Pregnancy can be performed only after 2 – 3 weeks of
    conception.
   LH is concerned with follicle maturation and ovulation.
   Menopausal hot flushes are due to LH surge.
   Estrogen increases the secretion and ciliary beating in fallopian tubes.
   Estrogen changes the cuboidal lining of vagina to stratified.
   Estrogen changes the break down of glycogen into lactate in vagina.
   Estrogen initiates breast development.
   Estrogen causes early epiphyseal closure.
   Estrogen causes water retention.
   Important     function   of   progesterone     is   to   promote   secretory   changes   in
    endometrium.
   Progesterone is the hormone for maintenance of pregnancy.
   Progesterone inhibits ovulation.
   The most important function of progesterone is to promote secretory changes in
    endometrium.


                  WATER & ELECTROLYTE / ACID-BASE BALANCE
   In human beings the total body water varies from 45 – 75 % of body weight.
   Total water in the body is about 40 liters. (ICF forms 55% & ECF forms 45%).
   The volume of interstial fluid is about 12 liters.
   The volume of plasma is about 2.75 liters.
   Osmolality is the measure of a fluid’s capability to create osmotic pressure, also
    called as osmotic conc. of a solution.
   Osmolarity is the no: of particles / per liter of solution.
   Isotonic solutions are having same effective osmolality as body fluids. Eg: 0.9%
    Nacl solution & 5% glucose solution.
   The insensible water loss from the body is about 600 to 800 ml. per day.
   The quantity of water lost as sweat per day is 600 – 800 C.C.
   The normal pH of plasma is 7.4
   Acidosis is pH below 7.38
   Alkalosis is pH above 7.42
   Respiratory acidosis: primary excess of carbonic acid


                                                                                             37
o   Due to hypoventilation as in respiratory diseases & neural diseases.
   Metabolic acidosis: primary deficiency of bicarbonate
       o   As in lactic acidosis, diabetic ketoacidosis, uremic acidosis & diarrhea.
   Respiratory alkalosis: primary deficiency of carbonic acid
       o   Due to hyperventilation as in hypoxia, neural diseases & psychological
           conditions.
   Metabolic alkalosis: primary excess of bicarbonate
       o   As in vomiting & treatment with diuretics.




                                                                                       38

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Physiology last-moment-revisions

  • 1. PHYSIOLOGY - Last moment revisions Muscle Physiology ·Muscle form 40 to 50% of body mass. ·About 600 muscles are identified. Classification of Muscles: ·Depending on striations: Striated(Skeletal & Cardiac) & Nonstriated(smooth) ·Depending on Control: voluntary(Skeletal) & Involuntary(Cardiac & smooth) ·Depending on situation: Skeletal, Cardiac & Smooth. ·Muscle fiber or cell has a length b/w 1 – 4cm (Average 3cm) & diameter from 10 – 100microns. ·1 myofibril contains 1500 myosin filaments & 3000 actin filaments ·Sarcomere is the structural & functional unit of skeletal muscle. Length – 2.5 to 3.2 mm. Sarcomere lies b/w two ‘Z’ lines ·Each myofibril consists of alternate light (I or J band) & dark band (A or Q band). ·Each sarcomere consist of thin (Actin) & thick (myosin) filaments. Myosin filament is present throughout the ‘A’ band. No movement of myosin during muscular contraction. ·Actin filaments are formed by 3 types of proteins called actin, tropomyosin & troponin. ·The skeletal muscle is formed by 75% of water, 20% of proteins & 5%of organic substances. ·Troponin: is formed by 3 subunits; Troponin I – attached to F actin; Troponin T – attached to tropomyosin; Troponin C – attached to calcium ions. ·Following are the muscle proteins; Myosin; Actin; Tropomyosin; Troponin; Actinin; Titin; Desmin; Myogen & Myoglobulin. ·There is no movement in the myosin filament during muscle contraction. ·Actin filaments slide over the myosin filament during muscle contraction. ·Tropomyosin covers the active sites of actin. ·Rheobase: this is the least possible, i.e. (minimum) strength (Voltage) of stimulus which can excite the tissue. ·Chronaxie: it is the minimum time, at which a stimulus with double the rheobasic strength (voltage) can excite the tissue. Chronaxie of skeletal muscle is shorter than that of cardiac and smooth muscles. Cold lengthens chronaxie. whereas vagal stimulation shortens chronaxie. 1
  • 2. ·Refractory period is the period at which the muscle does not show any response to a stimulus. ·Skeletal muscles are purely aerobic & don’t have any fuel reserve. ·Dark, light bands & troponin are absent in smooth muscle. ·The study of electrical activity of the muscle is done by electromyography. ·The muscle ruptures when it is stretched to about 3 times its equilibrium length. Cardiovascular system ·The syncytium of called physiological syncytium because there is no anatomical continuity of the fibers. ·SA node the pace maker is a small strip of modified cardiac muscle is situated in the superior part of lateral wall of right atrium, just below the opening of superior vena cava. · AV node is situated in the right posterior portion of interatrial septum. · Bundle of his run on either side of the interventricular septum. · Rhythmicity of different parts of heart: o SA node : 70 to 80 / min o AV node : 40 to 60 / min o Atrial muscle : 40 to 60 / min o Ventricular muscle : 20 to 40 / min · Velocity of impulse at different parts of the conductive system. o Atrial muscle fibres : 0.3 meter / second o Internodal fibers : 1.0 meter / second o AV node : 0.05 meter / second o Bundle of his : 0.12 meter / second o Purkinje fibers : 4 meter / second o Ventricular muscle fibers : 0.5 meter / second · Cardiac cycle includes systole & diastole which practically includes the events of ventricles. · When heart beats at the normal rate of 72/min, the duration of cardiac cycle is 0.8 sec. · The duration of systole is 0.27 sec & that of diastole is 0.53 sec. · The subdivision with duration are o Systole § Isometric contraction = 0.05 sec 2
  • 3. § Ejection period = 0.22 sec o Diastole § Protodiastole = 0.04 sec § Isometric relaxation = 0.08 sec § Rapid filling = 0.11 sec § Slow filling = 0.19 sec § Atrial systole = 0.11 sec § Total duration of cardiac cycle = 0.27 + 0.53 = 0.8 sec. · Atrial systole: atrial contract & a small amount of blood enter the ventricles. · Isometric contraction: all the valves are closed, ventricles undergo isometric contraction & pressure in the ventricles is increased. · Ejection period: semilunar valves opened, ventricles contract & blood is ejected out. · Protodiastole: this is the first diastole. The semilunar valves are closed at the end of this period. · Isometric relaxation: all the valves are closed, ventricles undergo isometric relaxation & pressure in the ventricles is reduced. · Rapid & slow filling: Atrioventricular valves are opened, ventricles relax & filling occurs. · Pressure difference Pressure Right Left Right Left Systemic Pulmonary Atrium Atrium Ventricle Ventricle Aorta artery Max (mm of 5–6 7–8 25 120 120 25 Hg) Min (mm of 0–2 0–2 2–3 5 80 7–8 Hg) · End systolic volume is 70 – 90 ml · End diastolic volume is 130 – 150 ml. 3
  • 4. · Cause for cardiac murmurs Systolic murmur Diastolic murmur Continuous murmur 1. Incompetence of AV 1. Stenosis of AV valve Patent valve 2. Incompetence of ductus 2. Stenosis of semilunar valves arteiosus semilunar valves 3. Anemia 4. Septal defect 5. Coarctation of aorta · Electrocardiography: Duration o Interval B/W 2 thick lines: (5mm) = 0.2 second o Interval B/W 2 thin lines (1mm) = 0.04 second Amplitude o Interval B/W 2 thick lines: (5mm) = 0.5 mV o Interval B/W 2 thin lines (1mm) = 0.1 mV Speed of the paper o 25 mm or 50 mm / second § Normal heart rate is 72 / min § Tachycardia: increase heart rate above 100 / min. Waves of normal ECG Wave / From – to Cause Duration Amplitude segment (second) (mV) Atrial 0.1 0.1 to 0.12 P wave - depolarization Ventricular 0.08 – 0.10 Q=0.1 – 0.2 QRS - repolarization R=1 complex S=0.4 Ventricular 0.2 0.3 T wave - repolarzation Onset of P Atrial 0.18 (0.12 to P – R wave to depolarization & 0.2) - interval onset of Q conduction through wave AV node 4
  • 5. Onset of Q Electrical activity in 0.4 – 0.42 Q – T wave & ventricles. - interval end of T wave End of S 0.08 ST wave & - - segment onset of T wave · In hyperkalemia, ECG shows a tall T wave. · In hypokalemia, ECG shows depressed S-T segment. · Heart sounds. Heart Occurs Cause Characteristics Duration Relation sounds during (sec) to ECG First Isometric Closure of Long, soft, & 0.10 – ‘R’ wave contraction AV valves low pitched. 0.17 & ejection Resembles the period word ‘LUBB’ Second Protodiastole Closure of Short, sharp, 0.10 – Precedes & part of semilunar & high pitched. 014 or isometric valves Resembles the appears relaxation word ‘DUBB’ 0.09 sec after summit of ‘T’ wave Third Rapid filling Rushing of Low pitched 0.07 – B/W ‘P’ blood into 0.1 wave & ventricles ‘Q’ wave. Fourth Atrial systole Contraction Inaudible 0.02 – B/W ‘P’ of atrial sound 0.04 wave & musculature ‘Q’ wave § Bradycardia: decrease in rate below 60 / min. 5
  • 6. ·Arrhythmia: irregular heart beat. § Sinus tachycardia: increase in discharge of impulse from SA node, upto 100 / min § Sinus bradycardia: reduction in the impulses from SA node, about 40 / min § Atrial flutter: Atrial rate is about 250 – 350 / min § Atrial fibrillation: rate of 300 – 400 beats / min § Ventricular fibrillation: rate is about 400 – 500 / min § Bain Bridge reflex (venous reflex) is characterized by reflex increase in Heart rate on venous engorgement of the right atrium. § Mary's law states that the Heart rate and Blood pressure have inverse relationship. § Stokes Adams syndrome is characterized by repeated fainting attacks associated with complete heart block. · Cardiac Output: o The amount of blood pumped from each ventricle. · Stroke volume: the amount of blood pumped out by each ventricle during each beat - 70ml. o Stroke volume at rest is 80 - 100 ml. · Minute volume: amount of blood pumped out by each ventricle in one minute. Minute volume = stroke volume X heart rate. – 5 liters/per ventricle/minute. · Cardiac Index: the minute volume from ventricle expressed in relation to square meter of body surface area. Normal value: 2.8 ± 0.3 liters / 1 square meter of body surface area / minute. · Ejection fraction: the fraction of end diastolic volume that is ejected out by each ventricle. Normal – 60 to 65%. · Cardiac reserve: the maximum amount of blood that can be pumped out by the heart above normal value. Normal healthy adult: 300 – 400%. · Variations in Cardiac output: (Physiological) o Less in children, females, early morning, changing from recumbent to upright position & in sleep. o Increased in males, greater body build, day time, emotional upset, after meals, after exercise, high attitude, 6
  • 7. and later months of pregnancy. · Distribution of Cardiac output: Organ Amount of blood Percentage Liver 1500ml 30% Kidney 1300ml 26% Skeletal muscles 900ml 18% Brain 800ml 16% Skin, bone & GIT 300ml 6% Heart 200ml 4% Total 5000ml 100% · Factors maintaining Cardiac output: 1. Venous return § Respiratory pump; Muscle pump; Gravity; Venous pressure; Vasomotor tone. 2. Force of contraction 3. Heart rate 4. Peripheral resistance · Regulation of Heart rate: 1. Vasomotor center: bilaterally situated in the reticular formation of medulla oblongata & lower part of pons. 2. Motor nerve fiber of heart. 3. sensory nerve fiber · Haemodynamics: Factors maintaining volume of flow of blood. · Pressure gradient; Resistance to blood flow; Viscosity of blood; Diameter of blood vessels; Velocity of blood flow: · Arterial Blood pressure: · Systolic pressure: maximum pressure exerted in the arteries during the systole of heart. Normal: 120 mmHg. (range 110 – 140) · Diastolic Blood Pressure: minimum pressure in the arteries during the diastole of the heart. Normal: 80 mmHg (range 60 – 90) · Pulse pressure: Difference between the systolic pressure & diastolic pressure. Normal: 40 mmHg. 7
  • 8. · Mean arterial blood pressure: this is the diastolic pressure plus one-third of pulse pressure. Normal: 93 mmHg. · Variations (Physiological) o Less in children, females before menopause, early morning & in sleep. o Increased in males, greater body build, and day time, after meals, after exercise, sleep with dreams. · Determinants of Arterial blood pressure: Cardiac output; Heart rate; Peripheral resistance; Venous return; Elasticity & Diameter of blood vessels; Velocity of blood flow; Viscosity of blood · Regulation of Arterial blood pressure: o Nervous mechanism: by vasomotor center & impulse from periphery o Renal mechanism: by regulation of ECF volume & rennin-angiotensin mechanism. o Local mechanism Local vasoconstrictors & Local vasodilators o Hormonal mechanism: Hormones increase BP Hormones decrease BP Adrenaline Vasoactive intestinal Noradrenaline polypeptide(VIP) Thyroxine Bradykinin Aldosterone Prostaglandin Vasopressin Histamine Angiotensin Acetylcholine Serotonin Atrial natriuretic peptide · Venous pressure: o Venous pressure in Jugular vein: 5.1 mmHg (6.9 cm H2O) o Venous pressure in superior vena cava: 4.6 mmHg (6.2 cm H 2O) o Portal venous pressure: 10 mm Hg o Hepatic venous pressure: 5 mm Hg. · Capillary pressure: o Capillary pressure in the arterial end is about 30 – 32 mmHg & venous end is about 15 mmHg. o It is high in Kidney (glomerular capillary pressure), about 60 mmHg – responsible for filtration. o Low in lungs (pulmonary capillary pressure), about 7 mmHg. 8
  • 9. · Venous pulse: (it is the pressure changes transmitted in the form of waves from right atrium to the veins near the heart) o Recording of JVP is called phlebogram. o Phlebogram has 3 positive waves – a, c & v and 3 negative waves – x, x1 & y. o ‘a’ wave – 1st positive wave & it’s due to atrial systole. o ‘x’ wave – fall of pressure in atrium, coincides with atrial diastole o ‘c’ wave – its due to rise in atrial pressure during isometric contraction during which the AV valves bulges into atrium. o ‘x1’ wave – occurs during ejection period, when AV ring is pulled towards ventricles causing distension of atria. o ‘v’ wave – occurs during isometric relaxation period or during atrial diastole. o ‘y’ wave – due to opening of AV valve & emptying of blood into ventricle. Nervous system · Neuron is defined as the structural & functional unit of nervous system. · Neuron does not have Centrosome so it cannot undergo division. · Nissl bodies are organelles containing ribosomes & are concerned with synthesis of protein in neurons. · Dendrites are conductive in nature & transmit impulses towards the nerve cell body. · Axons are longer process of the nerve cell concerned with transmission of impulse away from the nerve cell body. · The myelin sheath envelops the axon except at its ending and at the nodes of Raniver. · Myelin sheath is responsible for faster conduction of impulse through the nerve fiber & also acts as an insulating material. · Neurotrophins are the substances, which facilitate the growth, survival & repair of the nerve cells. · A alpha (Type Ia) nerve fiber is said to be the fastest nerve with a velocity of conduction of 70 to 120 meters / second. · Glial cells are very abundant and as many as 10 to 50 times as neurons. · Astrocytes form supporting network in brain & spinal cord, form basis for blood brain barrier. · Microglia is phagocytic in function. · Oligodendrocytes are responsible for the formation of myelin sheath in CNS because schwann cells are absent there. · Receptors: 9
  • 10. o Exteroceptors: give response to stimuli arising from outside the body. (Cutaneous, Chemoreceptors & Telereceptors) o Interoceptors: give response to stimuli arising from within the body. o Cutaneous receptors: § Touch receptors: Meissner’s corpuscle & Merkel’s disc (max in lips & fingers) § Pressure receptors: Pacinian corpuscles § Temperature receptor o Cold: Krause’s end organ o Warm: Raffini’s end organ o Warm receptors respond at body temperature of— 30 - 45°C. o Cold receptors are activated at body temperature of— 10°C or below. o Warm Sensation is carried by — C Fibres. o Cold Sensation is carried by — A. & C fibres. § Pain receptors: free (naked) nerve ending. (sensation which return earliest on recovery) o Chemoreceptors: § Taste: Taste buds § Smell: Olfactory receptors § Hearing: hairs cells of organ of corti in the internal ear. § Vision: Rods & Cones in retina – for visual sensation. o Viseroreceptors: § Stretch receptors, baroreceptors, chemoreceptors & Osmoreceptors o Proprioceptors: give response to change in position – labyrinthine, muscle spindle, golgi tendon, pacinian corpuscle, muscle, tendon & fascia. · Neurotransmitters: o Excitatory neurotransmitter: is responsible for the conduction of impulse from the presynaptic neuron to the postsynaptic neuron. o Inhibitory neurotransmitters: inhibits the conduction of impulse from the presynaptic neuron to the postsynaptic neuron. Group Name Action GABA Inhibitory Amino acids Glycine Inhibitory Glutamate Excitatory 10
  • 11. Aspartate Excitatory Adrenaline Inhibitory & Excitatory Noradrenaline Inhibitory & Excitatory Amines Dopamine Inhibitory Serotonin Inhibitory Histamine Excitatory Nitric oxide Excitatory Others Acetylcholine Excitatory · Superficial reflexes: Reflex Stimulus Response Center Corneal Irritation of cornea Blinking of eye Pons Conjunctival Irritation of Blinking of eye Pons conjuctiva Nasal Irritation of nasal Sneezing Motor mucus membrane nucleus of V cranial nerve Pharyngeal Irritation of Retching of Nuclei of X pharyngeal mucus gagging cranial nerve membrane Uvular Irritation of Uvula Raising of Uvula Nuclei of X cranial nerve · Superficial cutaneous reflexes Reflex Stimulus Response Center – spinal segment involved Irritation of skin at the Contraction of interscapular space scapular muscles & Scapular C5 to T1 drawing in of scapula Stroking the Ipsilateral Upper abdominal wall below contraction of T6 to T9 abdominal the costal margin abdominal muscle & movement of 11
  • 12. umbilicus towards the site of stroke Stroking the Ipsilateral abdominal wall at contraction of Lower umbilical & iliac level abdominal muscle & T10 to T12 abdominal movement of umbilicus towards the site of stroke Stroking the skin at Elevation of testicles Cremasteric upper & inner aspect L1, L2 of thigh Stroking the skin over Contraction of glutei L4 to S1, Gluteal glutei S2 Stroking the sole Plantar flexion & Plantar L5 to S2 adduction of toes Stroking the dorsum Contraction of Bulbocavernous S3, S4 of glans penis bulbocavernous Stroking the perianal Contraction of anal Anal S4, S5 region sphincter · Deep reflexes Reflex Stimulus Response Center – spinal segment involved Tapping middle of the Closure of mouth Pons – V Jaw jerk chin with slightly opened cranial mouth nerve Percussion of biceps Flexion of forearm Biceps jerk C5, C6 tendon Percussion of triceps Extension of Triceps jerk C6 to C8 tendon forearm Supinator jerk Percussion of tendon Supination & or radial over distal end (Styloid flexion of forearm C7, C8 periosteal process) of radius 12
  • 13. reflex Wrist tendon or Percussion of wrist Flexion of finger flexion tendons corresponding C8, T1 reflex finger Knee jerk or Percussion of patellar Extension of leg Patellar tendon ligament L2 to L4 reflex Ankle jerk or Percussion of Achilles Plantar flexion of Achilles tendon tendon foot L5 to S2 reflex Pathological reflexes: Babinski’s sign: there is dorsiflexion of great toe & fanning of other toes. Seen in UMN lesion, also in infants & normal persons with deep sleep. Spinal cord: Extends from foramen magnum to 1st lumbar vertebra. Length – 45 cm in male & 43 cm in females. Below the lumbar enlargement, the spinal cord rapidly narrows to a cone shaped termination called Conus medullaris. Spinal corresponds to 31 pairs of spinal nerves. (C-8; T-12; L-5; S-5; C-1) Grey matter is the collection of nerve cell bodies, dendrites & parts of axons. White matter is a collection of myelinated & nonmyelinated nerve fibers. Neurons in the grey matter of spinal cord Neurons in Anterior gray horn Alpha motor neurons; Gamma motor neurons & Renshaw cells Neurons in lateral gray horn Intermediolateral horn cells Neurons in posterior gray horn Substania gelatinosa of Rolando; Marginal cells; Chief sensory cells & Clarke’s column of cells. Ascending tracts of Spinal cord: Situation Tract Function Anterior white Anterior spinothalamic tract Crude touch sensation funiculus 13
  • 14. Lateral spinothalamic tract Pain & temperature sensation Subconscious kinesthetic Ventral spino cerebellar tract sensations Subconscious kinesthetic Dorsal spino cerebellar tract Lateral white sensations funiculus Spinotectal tract Concerned with spinovisual reflex Fasiculus dorsolateralis Pain & temperature sensations Spinoreticular tract Conciousness & awareness Spinoolivary tract Proprioception Spinovestibular tract Proprioception Tactile sensation Fasciculus gracilis Tactile localization Posterior Tactile discrimination white Vibratory sensation funiculus Fasciculus cuneatus Conscious kinesthetic sensation stereognosis Descending tracts of Spinal cord: Situation Tract Function Anterior corticospinal Pyramidal tract Control voluntary movements tracts Lateral corticospinal Forms upper motor neurons tract Medial longitudinal Coordination of reflex ocular movement fasciculus Integration of movements of eyes & neck Anterior vestibulospinal Maintenance of muscle tone & posture tract Maintenance of position of head & body Lateral vestibulospinal during acceleration Extra tract Coordination of voluntary & reflex Pyramidal movements. tracts Reticulospinal tract Control of muscle tone. Control of respiration & blood vessels. Control of movement of head in response to Tectospinal tract visual & auditory impulses. Rubrospinal tract Facilitatory influence on flexor muscle tone. 14
  • 15. Olivospinal tract Control of movements due to proprioception. Effect of upper motor neuron & lower motor neuron lesion: Effects upper motor neuron lower motor neuron lesion Muscle tone Hypertonic Hypotonic Paralysis Spastic type of paralysis Flaccid type of paralysis Wastage of muscle No wastage Present Clinical Superficial reflexes Lost Lost observation Plantar reflex Abnormal – babinski’s Absent sign Deep reflexes Exaggerated Lost Clonus Present Lost Electrical activity Normal Absent Muscles affected Groups of muscles are Individual affected muscles are Clinical affected confirmation Fascicular twitch in Absent present EMG Action of sympathetic & parasympathetic divisions of ANS: Effector organ Sympathetic division Parasympathetic division Eye Ciliary muscle Relaxation Contraction Pupil Dilatation Constriction Lachrymal secretion Decrease Increase Decrease in secretion & Increase in Salivary secretion vasoconstriction secretion & vasoconstriction Motility Inhibition Acceleration GIT Secretion Decrease Increase sphincters constriction Relaxation Gall bladder Relaxation contraction Urinary bladder Detrusor muscle Relaxation contraction Internal sphincter Constriction Relaxation Sweat glands Increase in secretion - Heart rate & force Increase decrease Blood vessels Constriction of all blood Dilatation 15
  • 16. vessels except those in heart & skeletal muscle Bronchioles Dilatation Constriction Resting membrane potential of various cells of the body. ·Resting membrane potential of a skeletal muscle is -90mV. ·Resting membrane potential of a smooth muscle is -50 to -75mV. ·Resting membrane potential of a cardiac muscle is -85 to -95mV. ·The resting membrane potential in the nerve fiber is -70mV. ·The resting membrane potential in the rods is -40mV. ·The resting membrane potential of inner ear cell is -60mV. Brain stem: (medulla oblongata, Pons & Midbrain) ·Pathway for ascending & descending tracts b/w brain & spinal cord. ·Important centers for regulation of vital functions in body. Medulla oblongata ·Respiratory centers: inspiratory & expiratory. ·Vasomotor center: B.P & Heart rate. ·Deglutition center: Pharyngeal & Oesophageal stage. ·Vomiting center: induce vomiting. ·Superior & inferior salivatory nuclei: controls secretion of saliva. ·Cranial nerve nuclei: nuclei of 10, 11 & 12 cranial nerves. ·Vestibular nuclei: Pons ·Bridge b/w medulla & midbrain. ·Forms pathway connecting cerebellum with cortex. ·Nuclei of 5 to 8th cranial nerve. ·Pneumotoxic & apneustic centers for regulation of respiration. Midbrain: (Consist of 2 parts Tectum & cerebral peduncles) ·Tectum: center for light & auditory reflexes. ·Cerebral peduncles: control of muscle tone ·Control of complex & skilled muscular movements, movement of eye balls Thalamus: Ovoid mass of gray matter, situated B/L in diencephalons) ·Relay center: for sensations (also called functional gateway). ·Center for integration of sensory impulses: determining the quality of sensations(discriminative & affective nature) ·Center for sexual sensations. 16
  • 17. ·Role in arousal & alertness reactions. ·Center for reflex activity ·Center for integration of motor functions. Hypothalamus: ·Control the secretion of Ant. & Post Pituitary hormones & adrenal cortex & medulla. ·Control of Autonomic nervous system; Heart rate; B.P; Body temp; Food intake (satiety, hunger &thirst); water balance; sleep & wakefulness. ·Role in behaviour & emotional changes. ·Regulation of sexual function & response to smell. ·Role in circadian rhythm. Cerebellum: ·Vestibulocerebellum: regulates tone, posture & receiving impulse for vestibular apparatus. ·Spinoncerebellum: regulates tone, posture & equilibrium by receiving impulses from proprioceptors in muscles, tendons & joints, tactile receptors, visual receptors & auditory receptors. · Corticocerebellum: concerned with the integration & regulation of well coordinated muscular activities. ·Different parts are represented in an upright manner in cerebellum. (opp: in cerebrum) Basal ganglia: (concerned with motor activities of extra-pyramidal system) ·Control of voluntary motor activity, muscle tone, reflex muscular activity, associated movements. ·Role in arousal mechanism. Cerebral cortex: Primary motor area Area 4 – center for movement (concerned with initiation of voluntary Area 4S – suppressor area. Pre Inhibits movements initiated by movements & speech) area 4. central Frontal cortex Area 6 – concerned with coordination of movements lobe (Post. initiated by area 4. Pre motor area Part) Area 8 – frontal eye field. Area 44 & 45(broca’s area) – motor area for speech. Supplementary Concerned with co-ordinated motor area skilled movements. Pre – Silent area or Area – 9 to 14, 23, 24, 29 & 17
  • 18. frontal association area 32. Center for planned action. cortex Center for higher Seat of intelligence. Personality functions – emotion, of individual. (Ant. learning, memory. Part) Area 1 – concerned with sensory perception Somesthetic area I Area 2 & 3 – integration of these sensations. Spatial Parietal recognition. Recognition of intensity, similarities & diff. B/W lobe stimuli Concerned with perception of Somesthetic area II sensation. Synthesis of various sensations Somesthetic association area perceived by S.Area-I. Stereognosis. Primary auditory area Area 41, 42 & wernicke’s area – concerned with perception of auditory impulses, Temporal analysis of pitch, determination lobe of intensity & source of sound Auditopsychic area Area 22 – interpretation of auditory sensation Area of equilibrium Maintenance of equilibrium Primary visual area Area 17 – perception of visual impulse Occipital Visual association area Area 18 - Interpretation of lobe visual impulses Occipital eye field Area 19 - Movements of eye Limbic system: (It is a group of cortical & sub cortical structures which form a ring around the hilus of cerebral hemisphere) ·Regulation of olfaction, autonomic functions (B.P, water balance & body temp). ·Control of circadian rhythm. ·Regulation of sexual function. ·Role in emotional state, memory & motivation. ·Retention of recent memory. ·Most developed part of Limbic System — Hippocampal formation ·Major efferent from Limbic system goes to — Mid brain reticular formation. ·Main function of Limbic system is to — Control the emotional behaviour. 18
  • 19. Proprioceptors: (These are receptors which give response to change in the position of different parts of the body). ·Muscle spindle: gives response to change in length of muscle. ·Golgi tendon organ: gives response to change in force developed in muscle. ·Pacinian corpuscle: pressure receptor in fascia, tendon & joints. ·Free nerve endings: Vestibular apparatus: ·Give response to rotatory movements or angular acceleration of the head. ·Responsible for detecting the position of head during different movements. EEG: (ELECTROENCEPHOLEGRAM) ·Alpha rhythm: Frequency: 8 to 12 waves / sec Amplitude: 50µU. Most marked in parieto-occipital area. Obtained in inattentive brain as in drowsiness & light sleep. ·Beta rhythm: Frequency: 15 to 60 waves / sec Amplitude: 5 - 10µU. Recorded during mental activity or mental tension or arousal state. ·Delta rhythm: Frequency: 1 to 5 waves / sec Amplitude: 20 - 200µU. Seen in tumour, epilepsy, increased intracranial pressure & mental depression. ·Theta rhythm: Frequency: 4 to 8 waves / sec Amplitude: 10µU. Seen in children below 5 years. SLEEP: ·Sleep requirement: Newborn infants: 18 to 20 hours. Growing children: 12 to 14 hours. Adults: 7 to 9 hours. Old persons: 5 to 7 hours. ·Types of sleep: Rapid eye movement sleep(REM) Non rapid eye movement sleep(NREM) 19
  • 20. Eye balls move Absent Dreams occur Absent Muscle twitching Absent 20 to 30% of sleep 70 to 80% of sleep ·Normal amount of C.S.F. in man is 150 C.C, ·Sympathetic nervous system is controlled by — Posterior hypothalamic nuclei ·Parasympathetic nervous system is controlled by — Anterior nuclei and part of middle nuclei of hypothalamus. EYE: §Refractory power is measured in dioptre (D). §Refractory power of cornea is 42D. §Refractory power of lens is 23D. §Refractory power of eye at rest is 59D. §Focal length of cornea is 24mm. §Focal length of lens is 44mm. §The wave lengths of visible light are approximately 397 to 723 nm. §There are about 6 million cones & 12 million rods in human eye. §Rods are responsible for dim light or night vision or scotopic vision. §Cones are responsible for colour vision, sensitive to day light & acuity of vision. §Rhodopsin is the photosensitive pigment of rods cells. §Photosensitive pigment in cones are o Porpyropsin – Red o Iodopsin – Green o Cyanopsin – Blue § Electroretinogram is the instrument to record the electrical basis of visual process. § Test for visual acuity – snell’s chart (distant vision) & Jaeger’s chart (near vision). § Test for color blindness – Ishihara’s colour chart. § Mapping of visual field – perimetry. § Nearest point at which the object is seen clearly is about 7 to 40cm. § Farthest point is infinite. § Myopia (short sightedness) is corrected by concave lens. § Hypermetropia (long sightedness) is corrected by convex lens. § Astigmatism is corrected by cylindrical lens. § Presbyopia is corrected by convex lens. EAR: 20
  • 21. § Ear is sensitive to sound between 1000 to 4000Hz range. § Hairs cells in organ of corti are the receptors for auditory sensation. § Sound becomes painful above 140db. § Auditory centers – 41, 42 & also auditopsychic area 22. TONGUE: § Sense organ of taste sensation is taste buds. § There are about 10,000 taste buds & each taste bud is replaced in every 10 days. § Each taste bud consists of 4 types of cells and is supplied by about 50 nerve fibres. § Receptors are type III cells of taste buds. § Taste center – opercular insular cortex (lower part of post central gyrus). § Bitter taste has very low threshold – 1 in 2,000,000. § Sweet taste has high threshold – 1 in 200. § Locations of taste buds are: sweet – tip; salt – dorsum; sour – side; bitter – posterior. SMELL: § Olfactory mucus consists of 10 to 20 million olfactory receptor cells. § Human nose can distinguish 2000 to 4000 different odours. GASTRO INTESTINAL SYSTEM  GIT is a tubular structures extending from the mouth up to anus with a length of about 30 feet.  A normal healthy adult consumes about 1kg solid diet & about 1 – 2 liters of liquid diet / day.  Auerbach’s plexus regulate the movements of GIT.  Meissner’s plexus regulate the secretory functions of GIT.  Auerbach’s plexus is present between the middle circular muscle layer & outer longitudinal muscle layer & its major function is to regulate the movements of GIT.  The total volume of GIT secretions per day is about 8000 ml.  Properties & composition of Saliva: · Volume: 1000 – 1500 ml / day, (70% by submaxillary glands). · Reaction: pH 6.35 – 6.85. · Specific gravity: 1.0002 – 1.012 · Composition: 99.5% water & 0.5% solids. · Digestive enzymes: salivary amylase (carbohydrate splitting) & lingual lipase (lipid splitting enzyme). 21
  • 22. · Substances like mercury, potassium iodide, lead & thiocyanate are excreted through saliva. · Saliva contains highest conc. of K+. · Volume of stomach is 50 ml when empty & can expand up to 4 liters. · Properties & composition of gastric juice: · Volume: 1200 – 1500 ml / day. · Reaction: pH 0.9 – 1.2. · Specific gravity: 1.002 – 1.004 · Composition: 99.5% water & 0.5% solids. · Digestive enzymes: Pepsin, Gastric lipase & other gastric enzymes. · Action of pepsin: attacks peptide bonds adjacent to aromatic amino acids by hydrolysis. · Action of gastric lipase: weak lipolytic enzyme becomes active only when pH is between 4 & 5. · Action of HCL: activates pepsinogen into pepsin, bacteriolytic action, causes acidity of the chime & provides acid medium for the action of enzyme. · Gastrin is one of the GIT hormones secreted by G cells present in pyloric glands of stomach. · Action of Gastrin: stimulates the secretion of pepsinogen & Hcl by gastric glands, increases the motility of stomach, secretion of pancreatic juice & production of hormones by pancreas. · Pancreas is a dual organ & has endocrine & exocrine function. · Properties & composition of Pancreatic Juice: · Volume: 500 – 800 ml / day. · Reaction: pH 8 – 8.3. · Specific gravity: 1.010 – 1.018 · Composition: 99.5% water & 0.5% solids. · An adult pancreas has 2.5-7.5 lac islets. · Total volume of pancreatic secretion per day is 2.5 liters. · Pancreas is the only organ that contains Trypsinogen. · Ascariasis can also cause acute pancreatitis. · Serum amylase and lipase levels are usually not elevated in chronic pancreatitis. · Duodenum is the principal site of iron absorption. 22
  • 23. · Most sensitive method for assessing pancreatic exocrine function is Secretin Stimulation Test.  Blood flow reaching the liver via portal versus hepatic artery is 4: 1.  Hepatic venous pressure is 5 mm Hg.  Most common complaints resulting from disorders involving the GIT include pain and alteration in bowel habit.  Most potent stimulus for bile secretion is bile salt.  Best stimulus for CCK secretion is Fat.  Properties of Bile: o Volume: 800 – 1200 ml / day o Reaction: alkaline o pH: 8 – 8.6 o Sp. Gty: 1010 - 1011  Composition of Bile: o Water: 97.6% o Solids: 2.4%  Bile is stored in gall bladder; it undergoes many changes in quality & quantity.  There is increase in conc. of bile salts, bile pigments, cholesterol, fatty acids & lecithin.  Functions of bile salts: o Emulsification of fats, due to emulsification, fat globules are broken down into minute particles. o Absorption of fats. o Stimulate the secretion of bile from liver. o Prevention of gall stone formation.  Properties of succus entericus: o Volume: 1800 ml / day o Reaction: alkaline o pH: 8 – 8.3 o Sp. Gty: 1010 - 1011  Enzymes of succus entericus: o Proteolytic enzymes: peptidases – amino peptidases, dipeptidase & tripeptidase. o Amylolytic enzymes: sucrase, maltase, isomaltase, lactase, dextrase & trehalase. 23
  • 24. o Lipase & enterokinase  Bacterial flora of large intestine synthesizes folic acid, Vit B12 & Vit K.  Vomiting center is situated bilaterally in medulla oblongata near the nucleus tractus solitarius.  Segmentation contraction & pendular movement are involved in mixing of food in small intestine.  Peristaltic movements peristaltic rush are the two movements involved in the pushing of chyme towards aboral end on intestine.  Desire for defecation is elicited by an increase in the intrarectal pressure to about 20 to 25 cm H2O.  Gastrointestinal hormones: Hormone Source of Actions secretion Gastrin G cells of 1. Stimulates the secretion of gastric stomach; juice. duodenum, 2. Increase the gastric motility. jejunum, Ant. Pit & Stimulates the release of pancreatic Brain hormones. Secretin S cells of Stimulates secretion of watery, duodenum, alkaline & pancreatic secretions. jejunum & ileum Cholecytokinin I cells in Stimulates contraction of gall bladder; duodenum, Activates secretin; Inhibits gastric jejunum & ileum motility; Increases secretion of enterokinase & intestinal motility. Gastric K cells in Inhibits secretion of gastric juice, inhibitory duodenum & gastric motility & increase insulin peptide (GIP) jejunum secretion.  Digestion of Carbohydrates: Area Juice Enzyme Substrate End Product Mouth Saliva Salivary amylase Polysaccharides Disaccharides Gastric Gastric amylase Weak amylase The action is Stomach juice negligible Small Pancreatic Pancreatic Polysaccharides Disaccharides – 24
  • 25. intestine juice amylase Disaccharides dextrins, maltose & maltriose Monosaccharides Succus Sucrase Disaccharides Glucose entericus Maltase Lactase Dextrinase Trehalase Skin  Skin is the largest organ in the human body.  The normal body temperature varies is between 35.8 – 37.30.  Axillary temperature is slightly lower, while rectal temp. is slightly higher.  Heat lose center is situated in pre-optic nucleus of ant. Hypo thalamus.  Heat gain center is situated in post. Hypothalamic nucleus.  Primary motor center for shivering is situated in post. Hypothalamus, near the wall 3rd ventricle. RESPIRATORY SYSTEM  The major phospholipids present in the surfactant are di-palmitoylphosphatidyl choline.  Surfactant is secreted by type II alveolar epithelial cells.  Total peripheral resistance falls about 50% in moderate exercise.  Cyanosis is detectable when arterial oxygen saturation falls below 75% corresponding to PO2 of 40 mmHg.  250ml of oxygen enters the body per min and 200 ml of CO2 is excreted.  5 ml of 02 is transported to the tissues by 100 ml blood in every cycle  Pulmonary alveolar macrophages form called "Dust cells".  Size and strength of respiratory muscles is 30-40% above normal in athletes whereas it is 20-30% less in physically weak people.  There are about 300 million alveoli in man.  There is no stimulation of ventilation by hypoxia until the alveolar O2 falls below 60 mm Hg.  Oxygen transported from lung to tissues in chemical combination is 97%.  In a healthy adult, 24 hour production of CO2 is about 330 liters.  Diffusion capacity for carbon dioxide as compared to that of 02 is 20 times. 25
  • 26. Average area of the alveolar walls in contact with capillaries in both lungs is about 70 sq. m.  Diffusion capacity of lungs for CO2 is 10-30 ml/min/mmHg.  Normal composition of venous blood is PO 2 - 40 mmHg, PCO2 -46 mm Hg and Hb saturation 75%.  Peak expiratory flow rate is 400-500 L/mt.  The presence of Hb increases the 02 carrying capacity of the blood by 70 fold.  Intra-pleural pressure (recoil pressure) required to prevent collapse of the lung — 4 mm Hg in presence of surfactant.  Intrapleural pressure at the end of deep inspiration is - 4 mm Hg.  Intrapleural pressure during expiration is - 2 mm Hg.  Compliance of the normal lungs and thorax combined — 0.13 liter/cm, of H2O.  Compliance of the normal lungs alone is 0.22 liter/cm of H2O.  During normal quiet breathing only 2-3% of the total energy expenditure is needed for pulmonary ventilation.  The amount of alveolar air replaced by new atmospheric air with each breath is only l/7th.  Expired air contains 2/3rd alveolar air + l/3rd dead space air.  63% of carbon dioxide is transported as bicarbonate form  97% of O2 is transported by Hb, rest 3% is in dissolved state in the water of the plasma and cells.  Carbon mono oxide binds with Hb. 230 times more strongly than ()2.  Under resting conditions each 100 ml of blood transports 5 ml of O2 to tissues and carries 4 ml of CO2 from tissues to the lungs.  Death occurs usually when the pH of the blood falls to 6.9.  The decrease in 02 affinity of Hb when the pH of blood falls is called Bohr’s effect.  The degree of stimulation of chemoreceptors depends on arterial PO2.  Spirometer cannot measure Functional Residual Capacity.  Functional residual capacity is measured by Nitrogen wash out or single breath oxygen method.  Most potent respiratory stimulant is carbon dioxide.  Kausmaul breathing is seen in diabetic ketoacidosis and it is not a feature of Hypercapnic acidosis.  Hering-breuer reflex: impulses from stretch receptors.  Peripheral chemoreceptors are carotid & aortic bodies. 26
  • 27. Respiratory centers: o Inspiration – dorsal group of neurons near tractus solitarius nucleus. o Expiration – ventral group situated in ventral part of medulla.  Normal value of FEV 1 in an adult male is 80%.  Muscles of Inspiration — Diaphragm and External Intercostals muscle (Others - Stcrnocleidomastoid, Serratus anterior).  Muscle of Expiration —Internal Intercostal muscle. (Rectus abdominis).  Intra alveolar pressure during inspiration — 1 mm Hg.  Tidal volume: 500 ml.  Inspiratory reserve volume: 3300 ml.  Expiratory reserve volume: 1000 ml.  Residual volume: 1200 ml.  Respiratory minute Volume in a normal person is 6.0 L/min.  Inspiratory capacity: 3800 ml.  Vital capacity : 4800 ml.  Total lung capacity: 6000 ml.  Functional residual capacity in a male is 2.2 liters.  Normal dead space air volume — 150 ml.  Timed vital capacity in 1sec is 83%.  Timed vital capacity in 2 sec is 94%.  Oxygen dissociation curve is ‘S’ shape or sigmoid shape. Shift to right Shift to left Decrease pH Increase pH Increase in temp decrease in temp Excess of 2, 3 DPG Foetal blood Increase PCO2 (Bohr effect) - Decrease PO2 - ENDOCRINE SYSTEM  Hormone which acts on the target cell is called as 1st messenger.  Cyclic AMP is the most common 2nd messenger for protein hormones.  Other 2nd messengers are Ca++, Calmoduline, Inositol triphosphate(IP3) & cyclic GMP.  Anterior pituitary hormones are o Growth hormone or somatotropic hormone 27
  • 28. o Thyroid stimulating hormone o Adenocorticotropic hormone o Follicle stimulating hormone o Luiteinizing Hormone or interstitial cell stimulating hormones in males o Prolactin.  Posterior pituitary hormones are o Antidiuretic hormone or vasopressin o Oxytocin  ADH causes conservation of body water & contraction of vascular smooth muscle.  Gigantism is due to the hyper secretion of growth hormone in childhood or in the pre-adult life before the fusion of epiphysis of bone with the shaft.  Acromegaly is due to hyper secretion of GH in adults after the fusion of epiphysis with shaft of the bone.  Dwarfism is a disorder of GH reduction in infancy or early childhood.  Diabetes insipidus is a syndrome developed due the defiency of ADH.  Hormone responsible for uterine contraction during labour & letting down of milk is Oxytocin.  The anterior pituitary has the largest blood flow of any tissue in the body.  Anterior pituitary hormones with diabetogenic effect – GH, ACTH, TSH, and PRL.  Pigmentation is not a feature of panhypopituitarism.  Hormones of thyroid gland are o Thyroxine (T4) – 90% o Triiodothyronine (T3) – 10% o Calcitonin  Potency of T3 is four times more than that of T4.  Graves’ disease is an auto-immune disease which causes hyperthyroidism.(exophathalmic goiter)  Cretinism is hypothyroidism in children & myxedema due to hypothyroidism in adults.  Parathormone is secreted by para thyroid gland & its main function is to increase the blood Ca++ level by mobilizing Ca++ from bone.  Calcitonin reduces the blood Ca++ level by decreasing the bone re-absorption.  Tetany results from hypocalcaemia, caused by hypoparathyroidism.  Pancreatic hormones are o Alpha cell – Glucagons 28
  • 29. o Beta cells – Insulin o Delta cells – Somatostatin o F or PP cells – Pancreatic polypeptide  Insulin is the only anti diabetic hormone secreted in the body.  Glucagons actions are antagonistic to that of insulin.  Somatostatin inhibits the secretion of both glucagons & Insulin.  Hormones of Adrenal cortex are o Mineralocorticoids (secreted by zona glomerulosa)  Aldosterone (↑ Na+ & excretion of K+)  11 deoxy corticosterone o Glucocorticoids (zona fasiculata)  Cortisol  Corticosterone o Sex hormones (zona reticularis)  Dehydroepiandrosterone  Androstenedione  Testosterone  Cushing syndrome is a disorder characterized by obesity due to hyper secretion of glucocorticoids.  Conn’s syndrome is primary aldosteronism.  Addison’s disease is chronic adrenal insuffiency.  Hormones of Adrenal medulla (Catecholamines) are o Adrenaline or epinephrine o Noradrenaline or norepinephrine o Dopamine  Pheochromocytoma is a condition in which there is excessive secretion of catecholamines.  Melatonin is secreted by parachymal cells of pineal gland, acts on gonads.  Severe stress can raise ACTH and cortisol level by 20 folds.  Fetal lung maturation depends on increased fetal Cortisol just before birth.  Human prolactin causes synthesis of milk in the female breast.  The half life of circulating growth hormone in humans is 20 to 30 minutes. 29
  • 30. BLOOD  Blood is a connective tissue in fluid form.  Blood is 5 times viscous than water.  Blood cell count is greater in children than adult.  RBC is microcytic in iron defiency anaemia, prolonged forced breathing & increased osmotic pressure.  RBC is macrocytic in megaloblastic anaemia, muscular exercise & decreased osmotic pressure in blood.  Punctate basophlism is seen in lead poisoning.  Goblet ring is seen in certain types of anaemia like malaria.  Red cell vol. can be determined by radio isotope 51 Cr.  Cyanosis appears when the reduced Hb cone, of the blood in the capillaries is more than 5 gm/dl.  In vitro, coagulation is initiated by factor XII.  Life of RBC's in adult human body is 120 days.  Average life span of RBC in a newborn is 100 days.  Average life span of RBC in transfused blood is 90 days.  Life span of transfused platelets is 4 days.  Life span of platelets is 9-12 days.  Complete erythropoiesis occurs in 7 days.  Erythropoiesis occurs in o In first trimester RBC's are formed in Yolk sac. While in second trimester liver is the main organ. Third trimester in liver & bone marrow. o Upto age of 5 – 6 yrs – red bone marrow of all bones. o 6 – 20 yrs – red bone marrow of all bones & all membranous bones. o After 20 yrs – all membranous bones & ends of long bone.  Hb starts appearing in intermediate normoblastic stage of erythropoiesis.  Nucleus disappears during late normoblastic stage.  Factors needed for Erythropoiesis: erythropoietin, thyroxine, interleukins 3, 6, 11, stem cell factors, Vit B, C & D. (maturation factors Vit B12 & folic acid).  The iron remains in ferrous state.  The affinity of Hb for CO2 is 20 times more than for O2.  The affinity of Hb for CO is 200 times more than its affinity for O2.  Adult Hb consists of 2 alpha & 2 beta chains.  Fetal Hb consist of 2 alpha & 2 gamma chains. 30
  • 31. In sickle cell anemia, the 2 alpha chains are normal but 2 beta chains are abnormal.  In Hb C, beta chains are abnormal.  Bilirubin is the final product formed from the destruction of Hb.  Total quantity of the iron in the body is 4gm.  1 mg of iron is excreted every day through faeces.  Normocytic normochromic anaemia is seen in aplastic aneamia.  Marcocytic normochromic anaemia seen in folate deficiency, Vit B12 & hypothyroidism.  Pernicious anaemia or addsion's anaemia is marcocytic normochromic anaemia.  Microcytic hypochromic is seen in iron deficiency, thalassemia, heamoglobinopathies & heamolytic anaemia.  ESR decreases in allergic conditions, sickle cell anaemia, polycythemia & afibrinogenemia. Character Normal 1. ESR Male: 3 – 7 mm / hr Female: 5 – 9 mm / hr 2. PCV (Packed cell Male: 40 – 45 % volume) Female: 38 – 42 % (Hematocrit) 3. MCV (Mean 90 cuµ (78 – 90 cuµ) corpuscular volume) 4. MCH (Mean 30 pg (27 – 32pg) corpuscular Hb) 5. MCHC (Mean 30% (13 – 38%) corpuscular Hb Conc.) 6. Colour index 1 (0.8 – 1.2) 7. WBC 4000 – 11,000 / cmm 8. D.C Neutrophils 50 – 70% Eosinophils 2–4% Basophils 0–1% Monocytes 2 – 6% Lymphocytes 20 – 30 % 31
  • 32. 9. Platelet count 2,50,000( 2 lakhs – 4 lakhs) 10. Bleeding time 3 – 6 min 11. Clotting time 3 – 8 min 12. Prothrombin time 12 sec 13. Activated partial 25 – 40 sec thromboplastin time(APTT) 14. RBC 4 – 5.5 millions / mm3 Adult male 5 millions / mm3 Adult female 4.5 millions / mm3 Birth 8 – 10 millions / mm3 15. Heamoglobin Adult male 14 – 18 gm / dl Adult female 12 – 16 gm / dl New born 16 – 22 gm /dl 16. RBC Diameter 7.5 µ 17. Blood volume 5 liters  Granulocytes are neutrophils, eosinophils & basophils.  Agranulocytes are monocytes & lymphocytes.  Monocyte is the largest lymphocyte.  In hemophilia clotting time is prolonged in presence of normal bleeding time.  Christmas disease occurs due to deficiency of factor IX.  Clotting factors Factor I Fibrinogen Factor II Prothrombin Factor III Thromboplastin Factor IV Calcium Factor V Pro accelerin (labile factor) Factor VI No such factor Factor VII Stable factor Factor VIII Anti hemophilic Factor IX Christmas 32
  • 33. Factor X Stuart-power Factor XI Plasma thrombplastin antecedent Factor XII Hegman (Conduct) Factor XIII Fibrin stabilizing factor (Fibrinase)  Blood group: Group Antigen in RBC Antibody in serum A A Anti – B (β) B B Anti – α AB A&B No anti body O No antigen Anti A & Anti B  Universal recipient are Blood Group 'AB because it does not contain either Anti A ab or anti B ab.  Universal donor is Blood Group "()" because it docs not contain either A or B agglutinogen (antigen).  Commonest blood group is O.  Diseases associated with blood groups: o Group A – C.A stomach o Group O – duodenal ulcer  Normal basic acid output is 5-10 mmol/hour.  Blood is stored in the blood bank at 40C.  The number of iron Heme in one Hb molecule is 4.  The number of O2 molecules carried by one Hb molecule is 4.  Mean corpuscular diameter is 7.5 nm.  Maximum concentration of Hb normally found in RBC's is 34%.  In arterial blood, saturated Hb with 02 is 97%.  Thromboxane A2 is synthesized by platelets and promotes vasoconstriction and platelet aggregation.  In sickle cell anemia, valine is substituted for glutamic acid.  Platelets are derived from megakaryocytes.  Pus contains — Dead neutrophils, macrophages and necrotic tissues.  Cardiac output in anemia is above normal while in polycythemia is about normal.  Agglutinins are either IgM or IgG.  In Erythroblastosis fetalis, mother is Rh-, father is Rh+, foetus is Rh positive.  Hapatoglobin is a plasma protein responsible for carrying free Haemoglobin.  Usual anticoagulant used for transfusion is a citrate salt. 33
  • 34. Earliest feature of iron deficiency anemia is decreased serum ferritin.  Arneth count is used in the determination of the percentage distribution of different types of neutrophils on the basis of no: nuclear lobes.  Wilson’s disease is due to decrease in caeruloplasmin. EXCRETORY SYSTEM  Hormones secreted by kidney are erythropoietin, thrombopoitein, renin & 1, 25 dihydroxy cholecalciferol.  1 kidney contains about 1 – 1.3 millions nephrons.  Ratio of corical nephrons to Juxtamedullary nephrons 85: 15.  The GFR of average sized normal man is approximately 125 ml / minute or 180 liters / day.  At the rate of 125 ml/min, the kidneys filter an amount of fluid equal to 4 times the TBV, 15 times the ECF vol. and 60 times the plasma volume.  1 – 1.5 liters of urine formed / day.  Urine osmolality in diabetes insipidus is 300 mmol/L.  Normal protein excretion is 50 -150 mg%.  The quantity of water lost as sweat per day is 600-800 C.C  Normal urea clearance is 44 ml/min.  Renal blood flow is 25% of cardiac output (1300 ml blood/min).  Total length of distal convoluted tubule is 5 mm.  Glomerulus membrane permits the passage of substances upto 4 nm and almost totally excludes substance with size greater than 8 nm.  Each glomerulus is a net work of approximately 50 parallel capillaries.  Urinary osmolality in diabetes insipidus is 300 m mol/Lit.  Glucose and amino acid are absorbed in proximal convoluted tubules by secondary active transport or sodium Co-transport.  Descending limb of thin segment of loop of Henle is freely permeable to water.  Areas impermeable to water — ascending limb of thin segment thick segment of loop of Henle. Proximal half of convoluted tubule.  Areas impermeable to urea — Distal convoluted tubule & cortical portion of collecting tubules.  Substances completely reabsorbed in PCT — Glucose, proteins, amino acids, vitamins, acetoacetate. 34
  • 35. Substances partially absorbed in PCT—Na. K, Cl (7/8 reabsorbed in PCT).  Substances secreted in PCT — H+, PAH (para amino hippurate). creatinine.  H+ are actively secreted in proximal tubules, distal tubules, collecting ducts.  Hyperosmilality in the interstitum is the prerequisite for excretion of concentrated urine.  Urea is reabsorbed from inner meduallary collecting ducts only in presence of ADH.  K+ is actively secreted in Late Distal tubules and Collecting ducts.  Macula densa is the epithelial cells of the distal tubule that comes to contact with the arterioles.  Juxtaglomerular cells produce renin.  Renin acts on angiotensinogen & convert it into angiotensin I.  Renal threshold for glucose is reduced in renal glycosuria.  Creatinine clearance represents GFR.  Clearance test for renal function includes inulin clearance, creatinine clearance & PAHA test.  PAHA test is performed to assess renal blood flow.  Micturition is primarily a spinal reflex.  Thick ascending loop of henle is impermeable to water.  Majority of sodium absorption occur in the proximal tubule. Character Normal pH 4. 5 – 6 Volume 1000 – 1500 ml / day Specific gravity 1.010 – 1.025 MALE REPRODUCTIVE SYSTEM  Average pH of semen is 7.5.  Life span of spermatozoa within the female genital tract is upto 24 hours.  Speed of human sperm in female genital tract is about 3 mm/min.  Male sex hormones are called the androgens (secreted by leydig cells); testosterone, dihydro testosterone & androstenedione.  Mullerian ducts gives rise to female accessory sex organs such as vagina, uterus & fallopian tube.  Wolffian duct gives rise to male accessory sex organs such as epididymis, vas deferens & seminal vesicles. 35
  • 36. Fetal testes begin to secrete the testosterone at about 2 nd to 4th month of embryonic life.  The secretion from seminal vesicles contains fructose, phophorylcholine, fibrinogen, ascorbic acid, citric acid, pepsinogen, acid phosphatase & prostaglandin.  Fructose & citrate acts as fuel for the spermatozoa.  Prostatic secretion is rich in enzymes, fructose & citrate.  Androgen appears to be essential for spermatogenesis. Whereas FSH is required for spermatic maturation.  Testes do not produce fructose.(seminal vesicle)  Sertoli cells provide nutrition to the developing sperm; secrete oestrogen & hormone binding proteins.  Testosterone is synthesized from pregnanolone.  Testosterone stimulates the process of spermatogenesis, also necessary for the formation of secondary spermatocyte from primary spermatocyte.  Growth hormone is essential for the general metabolic processes in testis.  Male sex hormone is secreted mainly by interstitial cells of Leydig.  Development of male sex organ in fetal life depends on testosterone produced under the influence of HCG.  Testosterone circulates in Combination with Gonadal steroid binding globulin.  Hormone used for treating osteoporosis in old age — Testosterone.  In males FSH promotes spermatogenesis by enhancing the transport of Testosterone to seminiferous tubules and androgen binding protein synthesis from sertoli cells. FEMALE REPRODUCTIVE SYSTEM  During menstrual period, upto 20 gm of protein may be lost.  Quantity of blood expelled during normal menstral cycle is 40 ml (approx) & serous – 35 mls.  FSH level is high in post menopausal women.  Ovarian hormones are estrogen and progesterone  Ovulation occurs on the 14th day of menstrual cycle in a normal cycle of 28 days.  Oxytocin causes contraction of smooth muscles of uterus & enhances labour.  Hormones secreted are HCG, Oestrogen, progesterone & human chorionic somato mammo tropin. 36
  • 37. Relaxin is a hormone secreted from the maternal ovary during the later periods of pregnancy.  Biological test for Pregnancy can be performed only after 2 – 3 weeks of conception.  LH is concerned with follicle maturation and ovulation.  Menopausal hot flushes are due to LH surge.  Estrogen increases the secretion and ciliary beating in fallopian tubes.  Estrogen changes the cuboidal lining of vagina to stratified.  Estrogen changes the break down of glycogen into lactate in vagina.  Estrogen initiates breast development.  Estrogen causes early epiphyseal closure.  Estrogen causes water retention.  Important function of progesterone is to promote secretory changes in endometrium.  Progesterone is the hormone for maintenance of pregnancy.  Progesterone inhibits ovulation.  The most important function of progesterone is to promote secretory changes in endometrium. WATER & ELECTROLYTE / ACID-BASE BALANCE  In human beings the total body water varies from 45 – 75 % of body weight.  Total water in the body is about 40 liters. (ICF forms 55% & ECF forms 45%).  The volume of interstial fluid is about 12 liters.  The volume of plasma is about 2.75 liters.  Osmolality is the measure of a fluid’s capability to create osmotic pressure, also called as osmotic conc. of a solution.  Osmolarity is the no: of particles / per liter of solution.  Isotonic solutions are having same effective osmolality as body fluids. Eg: 0.9% Nacl solution & 5% glucose solution.  The insensible water loss from the body is about 600 to 800 ml. per day.  The quantity of water lost as sweat per day is 600 – 800 C.C.  The normal pH of plasma is 7.4  Acidosis is pH below 7.38  Alkalosis is pH above 7.42  Respiratory acidosis: primary excess of carbonic acid 37
  • 38. o Due to hypoventilation as in respiratory diseases & neural diseases.  Metabolic acidosis: primary deficiency of bicarbonate o As in lactic acidosis, diabetic ketoacidosis, uremic acidosis & diarrhea.  Respiratory alkalosis: primary deficiency of carbonic acid o Due to hyperventilation as in hypoxia, neural diseases & psychological conditions.  Metabolic alkalosis: primary excess of bicarbonate o As in vomiting & treatment with diuretics. 38