4. DIET
• THE TOTAL FOOD INTAKE BY AN
ORGANISM.
• Nutrition – the supply of
nutrients.
5. NUTRIENTS
Essential Nutrients – must be consumed as part of your diet.
Cannot be synthesized by the body.
These four nutrients are essential:
• Water - essential
• Lipids – “fatty acid” essential
• Amino acids - not all
• Vitamins and Minerals – not all
Non-essential –
• Carbohydrates – energy can be made from both fats and
proteins
6. AMINO ACIDS
• 20 amino acids
Essential - lacking any a.a not made by the
body
Non essential – any that the body can
make by conversion of other nutrients.
8. FATS
• Storage of energy
• Insulation of body against temperature changes
• Fat around some organs provides shock
absorbers
• Cell membrane - phospholipid
9. VITAMIN AND MINERALS
• Can be distinguished by their chemical nature
Minerals –
• Chemical elements; usually ionic
Vitamins –
• All organic
Cannot be made by the body - essential
11. COMPARISON OF ENERGY
IN NUTRIENTS.
• Measured in kilojoules (kJ)
CARBOHYDRATES: 1760
kJ/100g
PROTEIN – 1720 kJ/100g
FAT – 4000 kJ/100g
12. MEASURING ENERGY CONTENT
• To heat one mL of water 1°celcius – 4.2J of energy is
needed = 1 calorie
• SO:
Energy content = temp change(ºC) x water volume(mL) x 4.2
of a food mass of food (g)
Calorimeter – instrument used to measure energy content
14. 3. READING NUTRITIONAL DATABASES
• VITAMIN AND MINERAL
• NUTRIENT DATABASE
• NUTRITONAL CONTENT IN FOODS
15. 4. LIPIDS, YOUR HEALTH, AND
HEART DISEASE
Review:
1. Saturated –
• All carbon atoms are connected by single covalent bonds
• Number of hydrogen atoms bonded to carbon cannot be increased
• Non essential
2. Unsaturated –
• One or more double bonds between carbon atoms
• More hydrogen can be bonded if double bond is replaced by
single bond.
16.
17. • SATURATED
• CHOLESTEROL
• TRANS FATS
• UNSATURATED
• MONOUNSATURATED
• POLYUNSATURATED
• CIS: OMEGA 3 & 7
GOOD FATS VS. BAD FATS
GOOD BAD
18.
19. FATTY ACIDS AND HEALTH - CHOLESTEROL
HDL vs. LDL – produced in the liver
CHOLESTEROL travels in the blood attached to a protein
• Low Density Lipoprotein – transports cholesterol and triglycerides from
the liver around the body…tends to deposit on artery walls.
• “Bad cholesterol” “Lousy”
• High Density Lipoproteins - transports excess cholesterol and
triglycerides from body to the liver.
• “Good cholesterol” “Happy”
Other source of FAT:
• Triglycerides - another type of fat produced by excess calories,
alcohol, and sugar (very LDL)
20.
21.
22. CHOLESTEROL AND CORONARY HEART DISEASE
• Cholesterol = steroid
Research has shown a positive correlation between high levels of
cholesterol and an increased risk of CHD, but it is not certain that
lowering cholesterol intake reduces the risk of CHD:
• Most research involves total blood cholesterol levels but
only cholesterol in LDL is implicated.
• The liver synthesizes it’s own cholesterol
• Reducing dietary cholesterol…very little overall effect on
CHD Rates
• Genetic factors appear to be more important
• There is a positive correlation between intake of saturated
fat and cholesterol. Is saturated fat the issue?
23. 4. APPETITE CONTROL AND THE
BRAIN
Hypothalamus - Appetite Control Center
Receives hormone stimuli:
• Insulin – secreted by pancreas when
Glucose levels are high
• Peptide YY36 - “gut hormone”
• Released by small intestine in
response to food intake
• Increases with number of calories
eaten
• Leptin – hormone released by
adipose tissue . More secreted as
more fat is stored.
• If hypothalamus receives hormone,
reduces desire to eat
24. 5. NUTRIENT DEFICIENCY DISEASES/DISORDERS
Malnutrition – a deficiency, imbalance,
or excess or specific nutrients in the
diet.
Starvation – severe lack of intake of
both essential and non-essential
nutrients.
• Results in breakdown of body tissue
25. VITAMIN AND MINERALS
• Can be distinguished by their chemical nature
Minerals –
• Chemical elements; usually ionic
Vitamins –
• All organic
Cannot be made by the body - essential
26. VITAMIN C
• Vitamin C = Ascorbic Acid
• Needed for synthesis of collagen fibers
in:
• Skin
• Blood vessel walls
• Humans cannot synthesize
• Not exclusive to humans
SCURVY – Vit. C deficiency disease.
Patients develop anemia, edema,
ulcerations, lose teeth.
28. VITAMIN D – DEFICIENCY
• Calciferol
• Oily fish, eggs, milk*
• Needed for calcium absorption in
the intestines.
• Calcium: bone and teeth strength
• Symptoms of deficiency similar to
calcium deficiency
• Diseases:
• Rickets – soft bone disorder
• Osteomalacia – bone thinning
• Synthesis:
• Skin, Food, Supplement
29. PROTEIN MALNUTRITION: PHENYLKETONURIA
CAUSES:
• Autosomal recessive – causes a mutation of the
gene for the enzyme PAH
• Condition where a baby is unable to breakdown
the a.a. phenylalanine into tyrosine.
• Deficiency in the enzyme PAH
• Levels of phenylalanine accumulate
30. PHENYLKETONURIA
• Most infants are tested soon after birth.
Symptoms:
Early: seizures, small head size
Long term – severe mental retardation
Treatment: diet low in phenylalanine
33. SOME GENERAL FACTORS
THAT LEAD TO OBESITY
• Food –
• high fat and sugar content
• Smaller quantities of high fiber
foods eaten
• Economic
• Growth – larger portions
• Food is cheaper
• Transport
• More cars ----less walking
• Jobs
• Physically undemanding
• Technology
• Tasks done by hand
--- now done by
machine.
•Video games and
television watching =
“couch potato”
generation!
35. TYPE II - DIABETES
• Diabetes Mellitus
• Adult Onset Diabetes
• Medical Cause:
• Auto immune destruction of insulin-
secreting cells in pancreas (TYPE 1)
• Decreased responsiveness of body cells
to insulin. (TYPE II)
36. TYPE II - DIABETES
Risk Factors:
• Obesity due to overeating
• Diets rich in fat/low in fibre
• Inactivity
• Genetics
• Ethnic background
37. TYPE II - DIABETES
Symptoms:
• Elevated blood/urine glucose
• Frequent Urination
• Dehyradtion/Increased thirst
• Extreme hunger
• Weight Loss
• Fatigue
• Slow healing and more frequent infection
38. COMPLICATIONS – TYPE II
DIABETES
If not carefully managed:
• Atherosclerosis/circulation issues
• Hypertension
• CHD
40. • Unusual obsession with food, weight, body shape, and
excessive exercise
• Affects more women than men
Psychological disorder:
• Emotional issues
• Perfectionism
• Control
• Self worth
41. PHYSICAL CONSEQUENCES
• Circulatory
• Anemia - bruising
• Low blood cell count & electrolyte balance
• Heart failure
• Respiratory – lung tissue
• Skeletal – bone loss; osteoporosis
• Muscle – loss of muscle mass, weaker
• Hair Loss
• Women – interruption of ovulation
• Men – low testosterone
44. STOMACH
The Basics:
• J – shaped muscular
organ. Thick walled
• Chemical and physical
digestion
• Sphincter – cardiac
and pyloric
• Stores food
• Begins protein
digestion….
45.
46. STOMACH
• Stomach lining:
• Contains Gastric Glands:
• Has three kinds of cells:
• Parietal: Secretes HCl –
activates pepsinogen; kills
pathogen.
• Chief: Secretes Pepsinogen;
activates to PEPSIN (gastric
protease) begins protein
digestion. pH – 2.
• Neck: Releases mucous;
provides protection
• Stomach processes food in
2-6 hours
• Semisolid food: chyme.
47. CONTROL OF GASTRIC JUICE SECRETION
• Controlled by nerves and hormones:
• Sight and smell of food sends nerve impulses to Parietal
cells – secretes acid (REFLEX)
• Na and Cl ions secreted. Water moves into stomach by
osmosis. Forms Gastric Juice.
• Chemoreceptors detect amino acids – move stomach
wall.
• Impulses are sent to brain. Brain sends impulses to
endocrine glands via VAGUS NERVE to secrete Gastrin.
• Gastrin stimulates further secretion of acid and
pepsinogen.
• Secretin and Somatostatin - inhibit gastrin secretion
50. SMALL INTESTINE
• Small diameter….7 meters long/ 23 ft (appx)
• Some physical; mostly chemical digestion.
• Receives secretions from the liver and
pancreas.
• 3 sections: duodenum (digestion), jejunum
(digestion and absorption) and ileum (for
absorption)
• Absorption of nutrients begins in the lining of
the small intestine.
51. SMALL INTESTINE - ENZYMES
• Bicarbonate – from pancreas to neutralize acid (not an enzyme)
• Protein –
• Trypsin - (pancreas) continues protein digestion. (pH 8)
• Endopeptidase - (small intestine) completes protein digestion
to amino acids (pH – 7.5)
• Fat –
• Bile – (liver) not an enzyme. Breaks down large fat molecules
• Lipase – (pancreas) digests fats. (pH – 8)
• Carbohydrates
• Amylase (pancreas) continues starch digestion (maltose) (pH
7)
• Maltase - (small intestine) = (maltose into glucose). (pH 7)
• Sucrase – glucose and fructose (pH – 7)
• Lactase – glucose and galactose (pH – 7)
52.
53. TISSUE OF THE DIGESTIVE TRACT
Mucosa
Epithelium
Longitudinal
Circular Muscle
59. SMALL INTESTINE - FOOD ABSORPTION
• Absorbed food travels to the liver for assimilation.
Structure Function
Finger-like shape Large surface area
Surface cell with – microvilli Huge increase in surface area
Surface cells with – enzymes Digestion
Surface cells with – large number of
mitochondria
Active transport
Dense capillary network Blood supply to remove water soluble
nutrients
Lacteal Removes end products of fat digestion.
Lipid soluble vitamins. Part of
lymphatic system
61. METHODS OF ABSORPTION
• Simple Diffusion – hydrophobic nutrients – fatty acids
• Facilitated Diffusion – hydrophilic nutrients (fructose)
• Active Transport – mineral ions….Na, Ca, Fe
• Endocytosis – Triglycerides, cholesterols
62. ASSIMILATION
• Taking molecules to cells to become part of the body:
• Carbohydrates: produce ATP, DNA, RNA, Cell membrane
• Fat: Adipose tissue, phospholipids, mitochondrial membranes,
hormones
• Amino acids: cells=proteins. Excessive amino acids are deaminated
by the liver to form urea
65. FUNCTIONS
• Composed of hepatocytes (Liver cells):
1. Detox: removes toxins from blood. Converts them to
less toxic/non-toxic.
2. Conversion of Cholesterol to Bile Salts: part of BILE.
Bile helps to emulsify fats in small intestine.
3. Production of Plasma proteins: rER of liver cells
produce 90% of plasma proteins (Albumin &
Fibrinogen). Processed by Golgi in liver cells
4. Nutrient storage and regulation:
• GLUCOSE STORAGE
• Iron, Vitamin A, Vitamin D
66. FUNCTIONS
5. Breakdown of Erythrocytes (RBC)
• Kupffer Cells – walls of sinusoids.
• Specialized macrophages that absorb and
breakdown RBC by phagocytosis.
• Recycle the components:
• Hemoglobin split
• Globins hydrolyzed
• Iron separates from heme – taken to
bone marrow
• Remainder of the heme forms
BILIRUBIN – used to form bile.
69. BLOOD FLOW (HEPATOCYTE)
• Blood is supplied by these vessels:
• HEPATIC PORTAL VEIN – blood from stomach, sm. Int. &
spleen directly to liver. Not a true vein. Bring nutrients to
liver.
• HEPATIC VEIN – blood -- no Oxygen to heart from liver
• HEPATIC ARTERY – blood supplies Oxygen from heart
• HPV separates into SINUSOIDS
• Capillary- like (wider), thin celled, many pores: allows blood
flowing through it to come in close contact to liver cells.
• HA branches to form capillaries that join sinusoids: provides
Oxygen to liver cells.
73. JAUNDICE
• Condition in which the skin and eyes become
yellow
• Due to accumulation of BILIRUBIN in blood
plasma
• Causes: Liver (Hepatitis or Cancer), Gall
Bladder (gall stones), Bile duct disease
• Result: could damage the brain, in infants –
cerebralpalsy
74. CHOLERA
• Infection of the intestines
• Source: Vibria cholerae (bacteria)
• Bacteria releases a toxin that binds to receptors in
the intestines.
• Toxin enters cells: endocytosis
• Toxin triggers release of Cl & HCO3 Water follows
leading to acute diarrhea.
• Fluid loss can cause death within hours
if untreated.
75. STOMACH ACID SECRETION AND
ULCERS
Stomach Acid
• secreted by parietal cells
• Disrupts ability of cells to be held
together in tissue
• Leads to denaturing of proteins
(except pepsin)
76. ACID REFLUX
• occurs when cardiac sphincter malfunctions
• Acid enters the esophagus
• Heartburn!
• Production of acid in stomach –
• proton pump (H+,K+ - ATPase Pump)
• Uses ATP to exchange 2H+ for 2K+
• Reduce Acid –
• Use of proton pump inhibitor (PPI)
• Bind to a single pump – irreversibly
• Provides temporary relief
• NEXIUM, PREVACID
77.
78.
79. ULCERS
• Open sore
• Partial digestion of stomach lining by pepsin/HCL
• Causes:
• Stress
• Excessive acid production
• Infection with Heliobacter pylori bacteria (80%)
• Lack of treatment can lead to stomach cancer
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The Heart and Blood Flow in
Mammals
General:
Double-sided pump.
Blood content:
Right: low in O2, high in
CO2
Left: high in O2, low in CO2
Basic Structure:
Right and Left side
separated by the SEPTUM.
Atrium – upper chambers.
Ventricles – lower
chambers.
Chambers separated by
valves
Flow from the heart
separated by valves.
86. Cardiac Muscle
Myogenic - ABILITY OF
THE HEART TO CONTRACT
WITHOUT BEING
STIMULATED BY AN
“OUTSIDE” NERVE.
Blood supplied by coronary
arteries.
Involuntary
Striated
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87. Properties of Cardiac Muscle
Intercalated discs –
separate cardiac
muscle cells.
Allows for rapid
movement of ions
Rapid conduction of
nerve impulse
Branched – allow
impulses to move
rapidly.
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Valves
VALVES
Atrioventricular – allows blood
to flow between atria and
ventricle
Semilunar – allows blood to
flow from ventricles
Cardiac Angiography
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CARDIAC CYCLE – Control of
the Heartbeat!!!
93.
94. Nodes
Sino Atrial – (SAN) –
Wall of right atrium
Pacemaker
Initiates contractions
Atrioventricular (AVN) –
Wall of lower RA.
Receives impulse from SAN
Connecting Fibers –
Bundle of His connected to Purkinje Tissue
pass through septum to base of heart to all
parts of the ventricles
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• The “pacemaker” sets the tempo of
the heartbeat.
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Cardiac Cycle
1. Walls of atria contract (Systole = 0-1)
SAN fires – ventricles about 70% full
Pushes blood from atria to ventricle
AV open; Semilunar closed
Ventricles fill; volume rises
2. Walls of ventricles contract(Systole = 1-4.2)
More powerful;
Initial rise in blood pressure in ventricles: AV valves close;
Further rise in BP: SL valves open
Blood PUMPED into aorta and pulmonary artery
Volume decrease
99. Events of the Cardiac Cycle
3. Ventricles stop contracting (diastole = 4.2-9)
Pressure falls
Semilunar valves close – prevents backflow
Blood pressure in Vena cava push blood
into atria
Ventricular pressure falls below atrial
pressure: AV valves open
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CONTROL OF HEARTRATE
1. Myogenic
1. Pacemaker – region of the heart (wall of R.A.)
responsible for initiating contraction.
2. Nerves from the brainstem carry messages
to pacemaker - speed up heartbeat
3. Adrenaline – carried to heart in blood ---
tells pacemaker to speed up heartbeat.
104. Measuring Heart Rate
Typically uses:
Radial artery in wrist
Carotid artery in neck
DO NOT USE THUMB!
It has its own pulse.
Variables affecting:
Demand for oxygen
Demand for glucose
Removal of CO2
Exercise
Body Position
Temperature
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106. Artificial Pacemakers
Inserted to treat
malfunctioning SAN OR
A block in the conduction
pathway.
Can provide a regular or
just when needed
impusle.
Regulates heart rate and
rhythm
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108. Defibrillators
Treats ventricular
fibrillation
Application of 2 paddles
in a diagonal line – with
the heart in the middle
Detects fibrillation
Electrical shock to return
to normal rhythm
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109. Stethoscopes and Heart Sounds
1st sound – closing of AV valve (lup)
2nd sound – closing of SL Valve (dup)
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110. Measuring Blood Pressure
Cuff placed around upper
arm (Brachial Artery)
Blood is constricted
Cuff slowly deflated
Stethoscope used for
sounds of blood flow
1st sound systolic
2nd diastolic
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