The document discusses various topics related to human nutrition: - It describes the essential nutrients that must be consumed as part of our diet, including water, lipids, some amino acids, and vitamins and minerals. - It then covers digestion, including the roles of the stomach, small intestine, liver, and heart. The stomach aids in protein digestion through gastric juices. The small intestine completes digestion with enzymes from the pancreas and bile from the liver. The liver performs many functions including detoxification and production of proteins and bile. The heart pumps blood throughout the body.

1. D.1 – HUMAN NUTRITION
D.2 – DIGESTION
D.3 – THE LIVER
D.4 – THE HEART
OPTION D

2. D.1 - HUMAN NUTRITION

3. 1. ESSENTIAL VS. NON
ESSENTIAL

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.

7. NON-ESSENTIAL VS. ESSENTIAL

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

10. 2. ENERGY
IN
HUMAN
DIETS

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

13. CALORIMETER

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.

17. • SATURATED
• CHOLESTEROL
• TRANS FATS
• UNSATURATED
• MONOUNSATURATED
• POLYUNSATURATED
• CIS: OMEGA 3 & 7
GOOD FATS VS. BAD FATS
GOOD BAD

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)

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.

27. SCURVY

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

31. PKU DIET

32. 6. CONSEQUENCES OF OBESITY

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!

34. TYPE II - DIABETES

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

39. ANOREXIA NERVOSA

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

42. PSYCHOLOGICAL CONSEQUENCES
• Depression
• Obsessive Compulsive
Disorder
• Drug Abuse
• Personality Changes

43. D.2 - DIGESTION

44. STOMACH
The Basics:
• J – shaped muscular
organ. Thick walled
• Chemical and physical
digestion
• Sphincter – cardiac
and pyloric
• Stores food
• Begins protein
digestion….

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

48. SMALL INTESTINE

49. SMALL INTESTINE

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)

53. TISSUE OF THE DIGESTIVE TRACT
Mucosa
Epithelium
Longitudinal
Circular Muscle

54. MICROGRAPH OF A CROSS
SECTION – SMALL INTESTINE

56. MICROGRAPHS OF THE SMALL
INTESTINE- TRANSVERSE VIEW

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

60. VILLUS

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

63. DISEASES OF THE DIGESTIVE SYSTEM
D.3 - THE LIVER

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.

67. KUPFFER CELLS

68. BLOOD FLOW THROUGH THE LIVER

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.

72. 7. DISEASES OF THE DIGESTIVE
SYSTEM

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

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

81. D.4 – THE HEART

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THE HEART

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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.

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The Mammalian Heart
INNER BODY

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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The Human Heart

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Valves and Nodes

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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!!!

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

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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.

102. Cardiology
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103. Basic Techniques in
Cardiology
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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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105. Electrocardiograms (ECG)
 P wave – atrial systole
 QRS – Ventricular
Systole
 T – ventricular
diastole
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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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107. Pacemakers
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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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111. Blood Pressure
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112. Hypertension and Thrombosis
 Causes – not clear
 Risk factors:
 Obesity
 Lack of exercise
 Too much salt
 Too much alcohol/coffee
 Smoking
 Genetic
 Consequences:
 Kidney damage
 CHD
 Causes:
 High LDL
 High SAT/TRANS FAT
 Inactivity
 Smoking
 Hypertension
 Ethnic
 Genetic
 Consequences:
 Heart Attack
 Stroke
 Atherosclerosis
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