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Review slides
Lecture Exam 2
1
Respiratory System
Respiration (in the respiratory system) is the process of
exchanging gases between the atmosphere and body cells.
It consists of the following events (in order):
• *pulmonary ventilation
• *external respiration
• transport
• internal respiration
• cellular respiration
Functions of the respiratory system
You should know
the order of these
events.
We breathe: 1. To provide O2 for cellular respiration and
2. To rid our bodies of CO2 (waste gas)
2
Organs of the Respiratory System
Upper respiratory tract
– nose, nasal cavity,
sinuses, and pharynx
Lower respiratory
tract – larynx, trachea,
bronchial tree, lungs
Conducting portion
carries air; nose to the
terminal bronchioles
Respiratory portion
exchanges gases;
respiratory bronchioles
and alveoli
3
1
Mucous in Respiratory Tract
Respiratory mucosa lines the conducting passageways and is
responsible for filtering, warming, and humidifying air.
Pseudostratified,
ciliated columnar
epithelium with
goblet cells
Respiratory epithelium
is interrupted by
stratified squamous
epithelium in the oroand laryngopharynx
4
Nose and Paranasal Sinuses
The nose:
1) warms
2) cleans
3) humidifies air
Figure from: Martini,
Anatomy & Physiology,
Prentice Hall, 2001
Be able
to label
this…
Paranasal sinuses are mucus membranelined, air-filled spaces in maxillary, frontal,
ethmoid, and sphenoid bones that drain into
the nasal cavity
Sinuses:
1. Reduce skull weight
2. Serve as resonating
chambers
5
Larynx
Prevents
swallowed material
from passing into
trachea
= major components of larynx
Inelastic
Vestibular folds
Covered by
folds of
laryngeal
epithelium
that project
into glottis
Protective
Posterior
Sound
Vocal folds (cords)
Elastic
Figure from: Martini,
Anatomy & Physiology,
Prentice Hall, 2001
6
2
Trachea & Primary Bronchi
Posterior
(S mooth muscle)
Note that the
trachea is
anterior to the
esophagus
(T5)
(T6)
Anterior
C-rings of cartilage: 16-20 incomplete rings
completed posteriorly by trachealis muscle
keep trachea open (patent)
Figures from: Martini, Anatomy & Physiology,
Prentice Hall, 2001
7
Bronchial Tree
Bronchi
Bronchioles
Alveolar structures
Primary
Alveolar ducts
Secondary (lobar)
Alveolar sacs
Tertiary (segmental)
Alveoli
Intralobular
Trachea
Terminal
Respiratory
conducting portion
respiratory portion
Know this chart
8
Bronchial Tree
Hilus of lung is the medial opening
for air passageways, blood vessels,
nerves, and lymphatics.
Bronchi
- Primary; w/ blood vessels
- Secondary (lobar);
two on left, three on right
- Tertiary (segmental); supplies
a broncho- pulmonary segment;
10
on right, 8 on left
Bronchioles
- Intralobular; supply lobules,
the basic unit of lung
- Terminal; 50-80 per lobule
- Respiratory; a few air sacs
budding from theses
Carina
Bronchioles are to the
respiratory system
what arterioles are to
the circulatory system
Figure from: Martini,
Anatomy & Physiology,
Prentice Hall, 2001
Intralobular
9
3
Lobules of the Lung
The Lobule is the
basic unit of
structure and
function in the lung
(Intralobular)
Terminal and respiratory
bronchioles are lined with
cuboidal epithelium, few
cilia, and no goblet cells
Figure from: Martini,
Anatomy & Physiology,
Prentice Hall, 2001
10
Gases and Pressure
• Our atmosphere is composed of several gases and
exerts pressure
– 78% N2, 21% O2, 0.4% H2O, 0.04% CO2
– 760 mm Hg, 1 ATM, 29.92” Hg, 15 lbs/in2,1034 cm H2O
• Each gas within the atmosphere exerts a pressure of
its own (partial) pressure, according to its
concentration in the mixture (Dalton’s Law)
– Example: Atmosphere is 21% O2, so O2 exerts a partial
pressure of 760 mm Hg. x .21 = 160 mm Hg.
– Partial pressure of O2 is designated as PO2
11
Normal Inspiration
• Intra-alveolar
(intrapulmonary)
pressure decreases to
about 758mm Hg as
the thoracic cavity
enlarges (P  1/V)
• Atmospheric
pressure (now higher
than that in lungs)
forces air into the
airways
• Compliance – ease
with which lungs can
expand
An active process
Phrenic nerves of the cervical plexus stimulate
diaphragm to contract and move downward and
external (inspiratory) intercostal muscles contract,
expanding the thoracic cavity and reducing
intrapulmonary pressure.
Attachment of parietal pleura to thoracic wall pulls
visceral pleura, and lungs follow.
12
4
Maximal (Forced) Inspiration
Thorax during normal
inspiration
Thorax during maximal inspiration
• aided by contraction of
sternocleidomastoid and pectoralis minor
muscles
Compliance
decreases as
lung volume
increases
Costal (shallow)
breathing vs.
diaphragmatic
(deep) breathing
13
Normal Expiration
• due to elastic recoil of the lung tissues and abdominal organs
• a PASSIVE process (no muscle contraction involved, no energy needed)
Normal expiration is
caused by
- elastic recoil of the
lungs (elastic rebound)
and abdominal organs
- surface tension
between walls of alveoli
(what keeps them from
collapsing completely?)
14
Maximal (Forced) Expiration
• contraction of
abdominal wall
muscles
• contraction of
posterior
(expiratory)
internal intercostal
muscles
• An active, NOT
passive, process
15
5
Terms Describing Respiratory Rate
• Eupnea – quiet (resting) breathing
• Apnea – suspension of breathing
• Hyperpnea – forced/deep breathing
• Dyspnea – difficult/labored breathing
• Tachypnea – rapid breathing
• Bradypnea – slow breathing
16
Know these
Alveoli and Respiratory Membrane
• Respiratory Membrane consists of the walls of the alveolus and the
capillary, and the shared basement membrane between them
Mechanisms that prevent alveoli
from filling with fluid:
1) cells of alveolar wall are tightly
joined together
2) the relatively high osmotic
pressure of the interstitial fluid
draws water out of them
3) there is low pressure in the
pulmonary circuit
Surfactant resists the tendency of alveoli to collapse on themselves.
17
Diffusion Through Respiratory Membrane
The driving for the exchange of gases between alveolar air
and capillary blood is the difference in partial pressure
between the gases.
alveolus
tissues
Because O2 and CO2 are relatively insoluble in H2O (plasma), RBCs are used
18
to carry or transform these gases.
6
Oxygen Transport
• Most oxygen binds to hemoglobin to form oxyhemoglobin (HbO2)
• Oxyhemoglobin releases oxygen in the regions of body cells
• Much oxygen is still bound to hemoglobin in the venous blood
Tissues
Lungs
But what special properties of the Hb molecule allow it to reversibly bind O2?
19
The O2-Hb Dissociation Curve
Recall that Hb can bind
up to 4 molecules of O2 =
100% saturation
At 75% saturation, Hb
binds 3 molecules of O2
on average
Sigmoidal (S) shape of
curve indicates that the
binding of one O2 makes
it easier to bind the next
O2
This curve tells us what the percent saturation of Hb will be at
various partial pressures of O2
20
Oxygen Release
Amount of oxygen released from oxyhemoglobin increases as
• partial pressure of carbon dioxide increases
• the blood pH decreases and [H+] increases (Bohr Effect; shown below)
• blood temperature increases (not shown)
• concentration of 2,3 bisphosphoglycerate (BPG) increases (not shown)
21
7
Carbon Dioxide Transport in Tissues
• dissolved in plasma (7%)
• combined with hemoglobin as carbaminohemoglobin(15-25%)
• in the form of bicarbonate ions (68-78%)
CO2 + H2O ↔ H2CO3
H2CO3 ↔ H+ + HCO3-
22
CO2 exchange in TISSUES
Carbon Dioxide Transport in Lungs
23
CO2 exchange in LUNGS
Summary of Gas Transport
PO2 = 40
mm Hg
PO2 = 100
mm Hg
PO2 = 100
mm Hg
L
U
N
G
S
T
I
S
S
U
E
S
PO2 = 40
mm Hg
PCO2 = 45
mm Hg
PCO2 = 40
mm Hg
PCO2 = 40
mm Hg
PCO2 = 45
mm Hg
24
CO2 + H2O ← H2CO3 ← H+ + HCO3-
H+ + HCO3- ← H2CO3 ← CO2 + H2O
8
Control of Respiration
• Control of respiration is accomplished by:
1) Local regulation
2) Nervous system regulation
• 1) Local regulation
–  alveolar ventilation (O2),  Blood flow to alveoli
–  alveolar ventilation (O2),  Blood flow to alveoli
–  alveolar CO2, bronchodilation
–  alveolar CO2, bronchoconstriction
25
Control of Respiration
• 2) Nervous System Control
– The DRG and VRG in medullary respiratory
rhythmicity center control rate/depth of breathing
• Changes in breathing
– CO2 is most powerful respiratory stimulant
– Recall: H2O + CO2 ↔ H2CO3 ↔ H+ + HCO3– Peripheral chemoreceptors (aortic/carotid bodies)
•  PCO2,  pH ,  PO2 stimulate breathing
– Central chemoreceptors (medulla)
•  PCO2,  pH stimulate breathing
26
Major Organs of Digestive System
Digestion is the mechanical and chemical breakdown of
food into a small enough form that cells can absorb
- Two major movements stimulating digestion: 1) segmentation
and 2) peristalsis
Organs can be divided into the:
-Digestive tract (primary) (alimentary canal); tube extending
from mouth to anus (about 30 ft.); in contact with food
-Accessory organs (secondary); teeth, tongue, salivary glands,
liver, gallbladder, and pancreas; provide secretions for digestion
27
9
Alimentary Canal Wall
Know the 4 layers of the alimentary canal
28
Figure from: Martini, Anatomy & Physiology, Prentice Hall, 2001
Innervation of the Alimentary Canal
The alimentary canal has extensive sympathetic and
parasympathetic innervation
- mainly in the muscularis externa
- regulates its tone and the strength, rate, and
velocity of muscular contractions
• submucosal plexus – controls secretions/blood flow
• myenteric plexus – controls gastrointestinal motility/sphincters
• parasympathetic division of ANS – increases activities of
digestive system and relaxes sphincters
• sympathetic division of ANS – generally inhibits digestive
actions and contracts sphincters
29
Palate
• roof of oral cavity
Figure from: Hole’s Human A&P, 12th edition, 2010
(adenoids)
Important in
separating the
nasopharynx
from the
pharynx
during
swallowing
Epiglottis prevents food from entering trachea during swallowing
30
10
Secondary (Permanent) Teeth
Figure from: Hole’s Human A&P, 12th edition, 2010
Total of 32
secondary
(permanent) teeth;
total of 20 primary
(baby, milk) teeth
Be able to
label this
diagram
16
1
I C Big Molars!!!
32
17
Know the
order of these
31
Functions of Saliva
• Moistens food
• Binds food particles
• Dissolves food for tasting
• Begins chemical digestion of complex CHO
(amylase)
• Cleans teeth and mouth (pH = 6.5 – 7.5)
• Anti-microbial (IgA and lysozyme)
32
Pharynx
Figure from: Hole’s Human A&P, 12th edition, 2010
Pharynx aids swallowing by grasping food and
moving it toward the esophagus.
33
11
Three Phases of the Swallowing Reflex
Only voluntary phase is the buccal (oral) phase, i.e., the initiation of swallowing,
then…
• soft palate and uvula raise
• hyoid bone and larynx elevate
Pharyngeal phase
• epiglottis closes off top of trachea
• longitudinal muscles of pharynx contract
reflexive
• inferior constrictor muscles relax and
esophagus opens
Esophageal phase
• peristaltic waves push food through pharynx
34
Esophagus conveys food from pharynx to stomach by peristalsis
Key
Overview of Gastric Control/Secretion
Emptying of
Stomach
(
[H+ ])
ECL Cells
+
+
+
+
D cells
-
G cells
+
Somatostatin
Inhibition
Endocrine Factor
Exocrine Factor
Histamine
Parasympathetic NS
+
+
Both
+
Stimulation
-
Mucous
Cells
Stomach Molility
(Segmentation/Peristalsis)
(cephalic/gastric phases)
pH < 3.0
+
Intrinsic
Factor
+
B12
Parietal Cells
H+ + Cl-
Gastrin
(intestinal
phase)
+
Fats in
Small
Intestine
+
+
+
Stretch
of
stomach
pH > 3.0
(dilution of H+)
HCO3- (alkaline tide)
+
Peptides
Chief
Cells
Pepsinogen
Pepsin
Protein
Breakdown
Food in
Stomach
Ileum
Fat
Breakdown
35
Lipases
Key
Regulation of Pancreas/Intestinal Digestion
+
Stimulation
Acidic Chyme Enters Duodenum
+
Secretin
+
+
Cholecystokinin
(CCK)
+
+
Gallbladder
Contraction
Bile and
Pancreatic
ducts
-,
(brush border)
+
Relaxation of
hepatopancreatic
sphincter
+
Pancreas
Enterokinase
Trypsinogen
Trypsin
Chymotrypsinogen
Procarboxypeptidase
Proelastase
Chymotrypsin
Carboxypeptidase
Elastase
(proenzymes, zymogens)
Bile
3-
HCO3 PO4
 pH to ≈ 8
(req. for enzyme
action)
(emulsification)
Triglycerides
Cholesterol
Fat Soluble Vitamins
Lacteals
Subclavian
vein
Proteins
Lipases
Fatty acids,
monoglycerides
Conversion to
chylomicrons
Nucleases
(DNA, RNA)
Nucleotides
Portal
Vein
Amylase
(glycogen,
starches)
Mono-, di-,
trisaccharides
Di- and
tripeptides
Action of
brush
border
enzymes
Monosaccharides
Amino acids
36
12
Liver Functions (over 200!)
• Three general categories of function
1) Metabolic regulation
•
•
•
•
•
Interconversion of carbohydrates, lipids, amino acids
Removal of wastes
Vitamin and mineral metabolism
Drug inactivation
Know items
Storage of fats, glycogen, iron, vit A/B 12/D/E/K
2) Hematological regulation
•
•
•
•
•
in red
Phagocytosis and antigen presentation; ab removal
Synthesis of plasma proteins
Removal of circulating hormones
Removal of worn-out RBCs (Kupffer cells)
Removal or storage of toxins
3) Synthesis and secretion of bile (digestion)
37
Paths of Blood and Bile in Hepatic Lobule
Figure from: Hole’s Human A&P, 12th edition, 2010
Liver’s role
in digestion is
production of
bile
Sinusoid
Hepatic portal vein → sinusoids → central vein → hepatic veins → inferior vena cava
Hepatic artery
38
Composition of Bile (Chole-)
Yellowish-green liquid continually secreted by hepatocytes
• water
• bile salts (bile acids)
• derived from cholesterol
• emulsification of fats (increases surface area for digestive enzymes;
large fat blobs become smaller blobs)
• absorption of fatty acids, cholesterol, and fat-soluble vitamins
• 80% are recycled (reabsorbed and reused) – enterohepatic
circulation of bile
• 20% excreted in feces (disposes of excess cholesterol)
• bile pigments (bilirubin and biliverdin from breakdown of RBCs)
• electrolytes
The hormone secretin, released by the small intestine, stimulates the
hepatocytes to produce a bicarbonate-rich bile that neutralizes acidic
chyme coming from the stomach
39
13
Gallbladder [Cyst(o)-]
Figure from: Martini, Anatomy &
Physiology, Prentice Hall, 2001
Main function is to store and concentrate bile between meals,
and release concentrated bile under the influence of CCK
40
Regulation of Bile Release from GB
Figure from: Hole’s Human A&P, 12th edition, 2010
• fatty chyme
entering duodenum
stimulates the GB to
release bile (via
CCK)
Secretin causes the bile ducts (and pancreatic ducts) to
secrete bile rich in HCO3-
41
Actions of Cholecystokinin (CCK) on Digestion
Figure adapted from: Barrett, K.,
Gastrointestinal Physiology, Lange,
2006
CCK
Contraction of
Gallbladder
Secretion of
pancreatic
enzymes
Reduced
emptying of
stomach
Relaxation of
hepatopancreatic
sphincter
Protein, CHO, lipid absorption and digestion
Matching of nutrient delivery to digestive and absorptive capability
42
14
Small Intestine
• Small Intestine
– Three major parts
• Duodenum – mixing chamber; mucus, buffers,
enzymes
• Jejunum – digestion and absorption
• Ileum – connects to cecum of large intestine
– Blood supply and drainage via superior
mesenteric artery/vein
– Surface area greatly increased, especially in the
jejunum, by
• Plicae
• Villi
• Microvilli
43
Know these things…
Small Intestine (cont’d)
– Secretions/Motility
• mucus secretion (protective) stimulated by presence of chyme in
small intestine
• distension of intestinal wall activates nerve plexuses in wall of small
intestine
• motility/secretion stimulated by gastroenteric reflex
• parasympathetics trigger release of intestinal enzymes
– Absorption
• Protein, CHO, electrolytes –> to hepatic portal vein into liver
• Fats via chylomicrons and lacteals -> circulation (2nd pass)
– Movements
• Local via myenteric plexuses
• Long distance via stomach filling
– Gastroenteric reflex
– Gastroileal reflex
44
Know these things…
Secretions of Small Intestine
• peptidase – breaks down peptides into amino acids
• sucrase, maltase, lactase – break down disaccharides into
monosaccharides
Brush
border
• intestinal lipase – breaks down fats into fatty acids and glycerol
• enterokinase – converts trypsinogen to trypsin
• gastrin/somatostatin – hormones that stimulate/inhibit acid secretion by
stomach
• cholecystokinin (CCK) – hormone that inhibits gastric glands, stimulates
pancreas to release enzymes in pancreatic juice, stimulates gallbladder to
release bile, and relaxes hepatopancreatic sphincter (of Oddi)
• secretin – stimulates pancreas to release bicarbonate ions in pancreatic
juice; stimulates gall bladder to release bicarbonate-rich bile
45
See Table 23.32 in Marieb for summary of digestive enzymes – great to use for XC!!
15
Absorption of Fats in the Small Intestine
Figure from: Hole’s Human A&P, 12th edition, 2010
• fatty acids and
glycerol
• several steps
• absorbed into
lymph into
blood
Chylomicrons contain TG, cholesterol, and phospholipids
46
Functions of Large Intestine
• little or no digestive function
• absorbs water, bile salts, and electrolytes
• secretes mucus (lubrication, binding, protection, pH)
• conversion of bilirubin (uro- and stercobilinogen)
• houses intestinal flora (~800 species of bacteria) and
absorbs vitamins liberated by bacterial action (K, B5,
and Biotin); produces intestinal gas (flatus)
• forms and stores feces
• carries out defecation
47
Large Intestine
Blood
supply/drainage via
superior mesenteric
arteries/veins
48
16
Movements of Large Intestine
• slower and less frequent than those of small intestine
• mixing movements (haustral churning every 30 min)
• mass movements - usually follow meals (stimulated
by distension of stomach and duodenum)
- gastrocolic reflex
- duodenocolic reflex
- peristaltic wave from transverse colon through
rest of large intestine
49
The Rectum, Anal Canal, and Anus
Figure from: Hole’s Human A&P, 12th edition, 2010
Temporary storage of
fecal material in
rectum triggers the
urge to defecate
Rectal
valves
Internal anal
sphincter is usually
contracted but relaxes
in response to
distension. External
sphincter must be
tensed to retain feces
Procto- = anus or rectum
50
(Keratinzed strat. squamous epithelium)
Parasympathetic Defecation Reflex
Note that this reflex:
1) relaxes (opens) the
internal sphincter and
2) constricts (closes) the
external sphincter
Need voluntary
relaxation of the external
sphincter for defecation
51
17
Nutrients
Nutrients – chemical substances supplied by the
environment required for survival (used for
growth, repair, or maintenance of the body)
Macronutrients
• carbohydrates
• proteins
• fats
Micronutrients
• vitamins
• minerals
Essential Nutrients
• human cells
cannot
synthesize
• include
certain fatty
acids, amino
acids, vitamins
52
Nitrogen Balance
Variety of compounds in the body contain nitrogen (N):
amino acids, purines, pyrimidines, creatine, porphyrins.
The body neither stores nor maintains reserves of N.
There’s only about 1 kg of N in body at any one time.
During starvation, N-containing compounds, like skeletal
muscle, are conserved; CHO and fats are metabolized first
(protein-sparing effect)
• nitrogen balance - amount of nitrogen taken in is equal to
amount excreted
• negative nitrogen balance develops from starvation
• positive nitrogen balance develops in growing children,
pregnant women, or an athlete in training
53
Body Mass Index
• occurs when caloric intake in the form of food
equals caloric output from BMR and muscular
activities
• positive energy balance leads to weight gain
• negative energy balance leads to weight loss
Body Mass Index (BMI)* = Wt (kg) / Height2 (m)
Thin
< 18.5
Healthy or Normal
18.5 – 24.9
Overweight
25.0 – 29.9
Obese
30.0 – 39.9
Morbidly Obese
 40.0
* Source: World Health Organization
54
18
Calculations of RDA/Maximums
• Energy yields:
– Protein, CHO = 4 Kcal/gm
– Fats = 9 (or 9.5) Kcal/gm
• No more than 30% of calories from fat
• RDA for protein = 0.8 g/kg body weight
– Recall: (2.2 lbs/kg)
55
Example Calculations - Fat
What is the maximum number of grams of fat to be
consumed per day for a patient on a 1500 calorie diet?
1) Find maximum number of CALORIES from fat:
1500 calories/day x 30% = 450 calories/day max from fat
2) Calculate number of GRAMS of fat in 450 calories
450 calories/day X 1 gram fat = 47 grams fat/day
9.5 calories
450 calories/day X 1 gram fat = 50 grams fat/day
9.0 calories
56
Example Calculations - Protein
What is the minimum number of grams of protein
recommended that should be consumed per day for a 175 lb
patient?
1) Find patient’s weight in Kg.
175 lbs X 1 Kg = 79.5 Kg
2.2 lbs.
2) Calculate number of GRAMS of protein required per day
79.5 Kg X 0.8 g protein/day = 63.5 grams protein/day
Kg
57
19
Summary of Lipoproteins
Designation
Origin
Action
Chylomicron
GI tract
Transports dietary fats
(mainly triglycerides) to liver
for processing
Very Low Density
Lipoprotein (VLDL)
Liver
Transports triglycerides from
liver to adipose cells
Low Density
Lipoprotein (LDL)
Liver
Transports cholesterol from
liver to cells in body
High Density
Lipoprotein (HDL)
Liver
Removes excess cholesterol
from cells and transports to
liver
58
The Fat-soluble Vitamins
• Absorbed with fats in digestive tract
• Function/Other sources
– Vitamin A; structural component of retinal
(night vision)
– Vitamin D
• increases absorption of calcium and phosphorus
from intestine
• skin and UV light
– Vitamin E
• stabilizes internal cellular membranes
• antioxidant
– Vitamin K
• Clotting (‘K’lotting)
• bacteria in intestine and green, leafy vegetables
59
Water-soluble Vitamins
• Rapidly exchanged between fluid compartments of
digestive tract and circulating blood
• Excesses excreted in urine
• Vitamins B12 and C are stored in larger quantities
than other water-soluble vitamins
– B vitamins [know these functions]
• as a group, are coenzymes used to harvest energy
• Vitamin B12 is important in hematopoiesis and maintenance of
myelin sheath and epithelial cells
– Vitamin C (ascorbic acid) [know these functions]
• collagen production
• Antioxidant / immune system booster
•  absorption of iron
60
20
Minerals
*Mineral
*Symbol
*Major/Trace
Primary
Distribution
*Major
Function(s)
Major
Sources
Conditions
*Calcium
Ca
Major
Bones & Teeth
Structure of
bone/teeth;
nerve impulse
conduction;
muscle contraction
milk;
+ kidney
stones
- stunted
growth
*Phosphorus
P
Major
Bones & Teeth
Structure of
bone/teeth;
ATP;
Nucleic acid &
proteins
meats;
cheese;
milk
+ none
- stunted
growth
*Potassium
K
Major
Intracellular Fluid
maintenance of resting
membrane
potential (RMP)
avocados;
bananas;
potatoes
+ none
- muscular &
cardiac
problem
s
*Sodium
Na
Major
Extracellular Fluid
maintenance of RMP,
electrolyte,
water, & pH
balance
table salt;
cured ham
+ hypertension,
edema
- cramps,
convulsi
ons
*Chlorine
Cl
Major
Extracellular Fluid
maintenance of RMP,
electrolyte, water, &
pH balance
table salt;
cured ham
+ vomiting
- muscle
cramps
61
Minerals
*Mineral
*Symbol
*Major/Trace
Primary
Distribution
*Major
Function(s)
Major
Sources
Conditions
*Magnesium
Mg
Major
Bones
needed in mitochondria
for cellular respiration;
ATP/ADP conversion
milk;
dairy;
legumes
+ diarrhea
- neuromuscular
problems
*Iron
Fe
Trace
Blood
part of hemoglobin
liver
+ liver
damage
- anemia
*Iodine
I
Trace
thyroid
essential in the
synthesis of thyroid
hormones
iodized
table salt
+ thyroid
hormone
imbalance
- goiter
*Zinc
Zn
Trace
liver, kidneys,
brain
wound healing; part of
several enzymes
meats;
cereals
+ slurred
speech
- decreased
immunity
62
Metabolism
-olysis  breakdown of
-genesis  creation of
-neo  new
Hormones:
Fed – Insulin
Fasted – Glucagon, Corticosteroids,
Epi/NE
• Glycolysis – metabolism of glucose to pyruvate (Fed)
• Gluconeogenesis – metabolism of pyruvate to glucose (CHO
from non-CHO source) – (Fasted)
• Glycogenesis – metabolism of glucose to glycogen (Fed)
• Glycogenolysis – metabolism of glycogen to glucose
(Fasted)
• Lipogenesis – creation of new triglyceride (fat) – (Fed)
• Lipolysis – breakdown of triglyceride into glycerol and fatty
acids (Fasted)
Major purpose of BOTH states is to maintain homeostatic levels of glucose in blood
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Basal Metabolic Rate
Basal metabolic rate (BMR)
• rate at which body expends energy at rest
(kcal/hr)
• primarily reflects energy needed to support
activities of organs
BMR is proportional
• varies with gender, body size, body
to body weight
temperature, and endocrine function
Energy needed
Body’s basal
• to maintain BMR
metabolic rate
• to support resting muscular activity
(BMR) falls 10%
• to maintain body temperature
during sleep and
• for growth in children and pregnant
about 40% during
women
prolonged starvation
BMR is profoundly affected by circulating
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thyroid hormone levels
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