This document provides information about the structure and function of the human brain and nervous system. It begins with definitions of the central nervous system (which includes the brain and spinal cord) and peripheral nervous system. It then describes the major parts of the brain - the cerebrum, cerebellum, brain stem, and diencephalon. It also discusses the somatic and autonomic nervous systems, comparing the sympathetic and parasympathetic divisions. Finally, it covers brain growth in the fetus and provides classifications of the nervous system.

2. Submitted to
Dr. Sikandar
Submitted by
M. Mubashar Beig
Roll No. 386-1503008
Group C
Section 1
Submitted to
Dr. Sikandar
Submitted by
M. Mubashar Beig
Roll No. 386-1503008
Group C
Section 1

3. “If the human brain were so
simple that we could
understand it, we would be
so simple that we couldn’t”
-Emerson Pugh, The
Biological Origin of Human
Values (1977)
If the human brain were
so simple that we could
understand it, we would
be so simple that we
couldn’t”
-Emerson Pugh, The Biological Origin of Human Values (1977)

4. Phineas Gage
 September 13th, 1848
 Phineas 25 years old
 Rutland & Burlington Railroad, Cavendish, VT
 Paving the way for new RR tracks
 “Tamping Iron”
 1.25in x 3ft

5. Phineas Gage
 Accident
 Quick Recovery
 Months later: “No longer Gage”
 Before: capable, efficient, best foreman, well-balanced
mind
 After: extravagant, anti-social, liar, grossly profane
 Stint with P.T Barnum
 Died 12 years later

6. Evolution of the Brain
Reptilian Paleomammalian Neomammalian

7. The Brain
weighs 1300 - 1400 g
made up of about 100 billion
neurons
“the most complex living
structure on the universe”
Society for Neuroscience
makes us who we are

8. The Brain
 The brain is responsible for many of the qualities that
make each individual unique-thoughts, feelings,
emotions, talents, memories, and the ability to process
information.
 Much of the brain is dedicated to running the body,
the brain is responsible for maintaining Homeostasis
by controlling and integrating the various systems that
make up the body.

9. Protection of Brain
 The Brain is Protected by a BONY Covering called the
SKULL.
The Brain is also WRAPPED in
THREE LAYERS of
CONNECTIVE TISSUE
known as the MENINGES.

10.  Connective Tissue connects one tissue to another.
 The INNER most layer, which covers and is bound to
the surface of the brain, is called PIA MATER. It is a
FIBEROUS LAYER made up of many Blood Vessels
which carry FOOD and OXYGEN to the Brain.
 The OUTER Layer, called the DURA MATER, is
composed of Thick Connective Tissue.

11.  The ARACHNOID is the THIN, elastic, weblike layer
between the PIA MATER and the DURA MATER.
Between the Pia Mater and the Arachnoid is a space
filled with CEREBROSPINAL FLUID.

12.  Cerebrospinal Fluid separates the middle and inner
Meninges and fills four interconnected VENTRICLES,
or Cavities in the Brain. Within the Ventricles,
Cerebrospinal Fluid acts as a Transport Medium for
substances that are important to Brain Function.

13.  The Cerebrospinal Fluid is a clear liquid that
PROTECTS the Brain from mechanical injury by
acting as a Shock Absorber.
 In order for the Brain to perform its functions, it must
have a constant supply of Food and Oxygen.
 If the Oxygen supply to the brain is cut off even for a
few minutes, the brain will usually suffer enormous
damage. Such damage may result in DEATH.

14. PARTS OF THE BRAIN

15. THE CEREBRUM

16. THE CEREBRUM
 THE CEREBRUM IS THE CONTROL CENTER OF
THE BRAIN.
 The LARGEST and most PROMINENT part of the
Human Brain is the CEREBRUM. 85% OF THE
WEIGHT OF A HUMAN BRAIN.
 The Cerebrum is responsible for all the VOLUNTARY
(CONSCIOUS) ACTIVITIES OF THE BODY. It is the
site of INTELLIGENCE, LEARNING AND JUDGMENT.

17. THE CEREBRUM
 IT FUNCTIONS IN LANGUAGE, CONSCIOUS
THOUGHT, MEMORY, PERSONALITY
DEVELOPMENT, VISION, AND OTHER
SENSATIONS.
 The Cerebrum takes up most of the space in the cavity
that houses the Brain. (SKULL)
 The CEREBRUM IS DIVIDED INTO TWO
HEMISPHERES, THE LEFT AND RIGHT
CEREBRAL HEMISPHERES.

18. THE CEREBRUM

19. THE CEREBRUM
 There is a DEEP GROVE that separates the Two
Hemispheres.
 The Hemispheres are Connected in a region known as
the CORPUS CALLOSUM.

20. THE CEREBRUM
 The right and left cerebral hemispheres are linked by a
bundle of neurons called A TRACT tells each half of
the brain what the other half is doing.
 The MOST Obvious FEATURE on the surface of each
hemisphere are NUMEROUS FOLDS.
 These FOLDS and the GROOVES INCREASE the
Surface Area of the Cerebrum. The Ridges are called
GYRI, and the grooves are called SULCUS.
 The Cerebrum, which looks like a wrinkled
mushroom, is positioned over the rest of the brain.

21. THE CEREBRUM
 It contains thick layers of Unmyelinated Neurons,
which look GRAY. ("GRAY MATTER")
 The increased surface
area permits the large
number of neurons to
fit easily within the
confines of the Skull.

22. Lobes of the cerebrum

23. Lobes of the cerebrum
 Each Hemisphere of the Cerebrum is divided into Four
regions called LOBES.
 These LOBES are named for the SKULL BONES that
cover them, FRONTAL, PARIETAL, TEMPORAL,
AND OCCIPITAL LOBES.

24. Frontal Lobe
• Found under your forehead.
• Center of reasoning
• Planning
• some parts of speech
• movement (motor cortex)
• Emotions
• problem solving.

25. Parietal Lobe
• Found on the top of your head.
• Receives sensory input from the skin. (touch,
pressure, temperature, & pain)

26. Occipital lobe
• Found at the back of your head.
• Receives input from the eyes
• Often referred to as the visual cortex

27. Temporal Lobe
• Found on the sides of your head above your ears.
• Functions include:
• speech perception
• hearing,
• some types of memory

29. THE CEREBELLUM
 The CEREBELLUM is the
SECOND LARGEST part of
the Brain, and is located at
the back of the Skull. It
coordinates muscle
movements

30. THE CEREBELLUM
 The Cerebellum coordinates and balances the actions
of Muscles so that the body can move gracefully and
efficiently.
 The Cerebellum CONTROLS BALANCE, POSTURE,
and COORDINATION.
 The Cerebellum receives sensory impulses from
muscles, tendons, joints, eyes, and ears, as well as
input from other brain centers.

31. THE CEREBELLUM
 It processes information about position and controls
posture by keeping skeletal muscles in a constant state
of partial contraction.
 The Cerebellum Coordinates rapid and ongoing
movements.
 This is a small CAULIFLOWER SHAPED Structure.

32. THE CEREBELLUM
 A Major part of learning how to perform physical
activities seems to be related to training the
Cerebellum to coordinate the proper muscles. Because
the function of the Cerebellum is INVOLUNTARY
(not under conscious control), learning a completely
new physical activity can be very difficult.

33. THE BRAIN STEM
 The BRAIN STEM CONNECTS the BRAIN to the
SPINAL CORD.

34. THE BRAIN STEM
 The brain stem, which maintains life support systems,
consist of the diencephalon, medulla oblongata, pons,
and the midbrain.
 The Brain Stem Controls Vital Body Processes.
 The Brain stem not only coordinates and integrates all
INCOMING INFORMATION; it also serves as the
place of entry or exit for ten of the Twelve Cranial
Nerves.

35. THE BRAIN STEM
 The Upper Brain Stem, the Diencephalon, contains
important relay centers for information entering an
exiting the brain.
 The Lower Brain Stem consists of the MEDULLA
OBLONGATA, PONS, AND MIDBRAIN.
 The Lowest Part of the Brain Stem is the Medulla
Oblongata (Sometimes just called the Medulla).

36. THE BRAIN STEM
 The Medulla contains WHITE MATER that conducts
impulses between the Spinal Cord and Brain.
 The MEDULLA controls involuntary functions that
include, breathing, blood pressure, heart rate,
digestion, swallowing, and coughing.
 Another important part of the Medulla is a GROUP of
CELLS known as THE RETICULAR ACTIVATING
SYSTEM or RETICULAR FORMATION (RAS).

37. THE BRAIN STEM
 The Reticular Activation System (RAS) actually helps
to alert, or awaken, the upper parts of the Brain,
including the Cerebral Cortex. Such actions keep the
Brain alert and conscious.
 The RAS also helps to control respiration and
circulation and serves as a filtering system for
incoming sensory signals. For example, we awaken to
the sound of an alarm clock, to a bright light flash, or
to a painful pinch because activity in the RAS that
arouses the Cerebral Cortex.

38. THE BRAIN STEM
 Just above the Medulla, the brainstem enlarges to form
the PONS. PONS mean BRIDGE, and this area of the
brain stem contains mostly white matter that provides
a link between the cerebral cortex and the cerebellum.
Above the PONS and continuous with it is the
MIDBRAIN, the smallest division of the lower brain
stem.

39. DIENCEPHALON
 THE THALAMUS AND HYPOTHALAMUS
 The Thalamus and Hypothalamus are found in the
part of the brain between the Brain Stem and
Cerebrum.
 The Thalamus, which is composed of Gray Matter,
serves as a SWITCHING STATION FOR SENSORY
INPUT. With the Exception of SMELL, each Sense
Channels its Sensory Nerves through the Thalamus.

40. DIENCEPHALON
 The Thalamus passes information to the proper region
of the Cerebrum for further processing.
 Immediately Below the Thalamus is the
Hypothalamus, which is the CONTROL CENTER for
hunger, thirst, fatigue, anger, and body
temperature.
 Parts of the Diencephalon and the Cerebrum are
included in an important group of connected Brain
Centers called the LIMBIC SYSTEM.

41. DIENCEPHALON
 The Limbic System includes the Thalamus, the
Hypothalamus, some deeper parts of the Cerebral
Cortex, and centers in the Temporal Lobes.
 The Limbic system plays an important role in
emotions, memory, and motivation, among other
things.

42. BRAIN GROWTH IN FETUS

43. Nervous System
The nervous system comprises the
central nervous system, consisting of
the brain and spinal cord, and the
peripheral nervous system, consisting
of the cranial, spinal, and peripheral
nerves, together with their motor and
sensory endings.

44. Classification Of Nervous System

45. Central nervous system
 The central nervous system is composed of millions of
nerve and glial cells, together with blood vessels and a
little connective tissue. The nerve cells, or neurons, are
characterized by many processes and are specialized
for reception and transmission of signals. The glial
cells, termed neuroglia, are characterized by short
processes that have special relationships to neurons,
blood vessels, and connective tissue.

46. Peripheral Nervous System
 A nerve is a collection of nerve fibers that is visible to the naked
eye. The constituent fibres are bound together by connective
tissue. Each fiber is microscopic in size and is surrounded by a
sheath formed by a neurilemmal cell (comparable to the glial
cells of the central nervous system). Hundreds or thou sands of
fibers are present in each nerve. Thus, according to the number
of constituent fibers, a nerve may be barely visible, or it may be
quite thick. A nerve as a whole is surrounded by a connective
tissue sheath, the epineurium. Connective tissue fibers run
inward from the sheath and enclose bundles of nerve fibers.
Such bundles are termed fasciculi (funiculi); the connective
tissue that encloses them is called perineurium. Very small
nerves may consist of only one fasciculus derived from the parent
nerve. Finally, each nerve fiber and its neurilemmal sheath are
enclosed by a connective tissue sheath termed endoneurium.

47. Somatic Nervous System
A collection of neurons that
carries messages from the
central nervous system to
muscle cells.

48. Autonomic nervous system
 A collection of neurons that carry messages from the
central nervous system to the heart, smooth muscles,
and glands generally not as a result of conscious action
on the part of the brain.
Autonomic nervous system is further divided into two
types
 Sympathetic nervous system
 Parasympathetic nervous system

49. Comparison Between Sympathetic
and Parasympathetic nervous system
Parasympathetic
nervous system
Sympathetic nervous
system
Introduction The parasympathetic
nervous system is one of
the two main divisions of
the autonomic nervous
system (ANS). Its general
function is to control
homeostasis and the
body's rest-and-digest
response.
The sympathetic nervous
system (SNS) is one of
two main divisions of the
autonomic nervous
system (ANS). Its general
action is to mobilize the
body's fight-or-flight
response.
Function Control the body's
response while at rest.
Control the body's
response during
perceived threat.

50. Originates in Spinal cord, medulla Spinal cord, thoracic
and lumbar spinal cord
Activates Response of Rest and digest Fight or Flight
Neuron Pathways Longer pathways, slower
system
Very short neurons, faster
system
General Body Response Counterbalance; restores
body to state of calm.
Body speeds up, tenses
up, becomes more alert.
Functions not critical to
survival shut down.
Cardiovascular System
(heart rate)
Decreases heart rate Increases contraction,
heart rate
Pulmonary System (lungs) Bronchial tubes constrict Bronchial tubes dilate
Musculoskeletal System Muscles relax Muscles contract

51. Pupils Constrict Dilate
Gastrointestinal System Increases stomach
movement and secretions
Decreases stomach
movement and secretions
Salivary Glands Saliva production
increases
Saliva production
decreases
Adrenal Gland No involvement Releases adrenaline
Glycogen to Glucose
Conversion
No involvement Increases; converts
glycogen to glucose for
muscle energy
Urinary Response Increase in urinary
output
Decrease in urinary
output