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human physiology > circulation and gas exchange 2 > Flashcards

circulation and gas exchange 2 Flashcards

1
Q

what is blood?

A

Blood is a connective tissue with cells suspended in plasma

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2
Q

what is serum?

A

Blood plasma with clotting factors removed is called serum

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3
Q

what are the types of cells suspended in blood as well as their functions?

A

-white blood cells (leukocytes): defence and immunity
-platelets: blood clotting
-red blood cells (erythrocytes): transport of O2 and some CO2

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4
Q

what are the components of plasma as well as their functions?

A
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5
Q

what’s in plasma?

A
  • carries the cells and cell fragments (red and white blood cells and platelets)
  • the transparent, straw-colored plasma consists of water, ions, various plasma proteins, nutrients, waste products, respiratory gases, and hormones
  • about 90% water.
  • includes ions (blood electrolytes) which
    maintaining osmotic balance and buffer the blood.
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6
Q

what does proper functioning of muscles and nerves depend on?

A

Proper functioning of muscles and nerves depends on the concentrations of ions in the interstitial fluid, which reflects concentrations in the plasma.

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7
Q

how does plasma help with transport?

A

Plasma carries a wide variety of substances in transit from one part of the body to another
1) nutrients
2) metabolic wastes
3) respiratory gases
4) hormones.

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8
Q

what do plasma proteins do?

A
  • buffer against pH changes.
  • help maintain osmotic balance
  • contribute to the blood’s viscosity.
  • specific proteins transport otherwise-insoluble lipids in the blood.
  • immunoglobulins (antibodies) help combat viruses and other foreign agents that invade the body.
  • Fibrinogen helps plug leaks when blood vessels are injured.
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9
Q
A
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10
Q

what do red blood cells do?

A

1) red blood cells (erythrocytes)
- transport oxygen
- the most numerous blood cells.

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11
Q

what do white blood cells do?

A

2) white blood cells
- function in defense

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12
Q

what are platelets?

A

platelets are pieces of cells
- also called thrombocytes
- involved in clotting

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13
Q

what are the types of white blood cells? (leucocytes)

A

-neutrophils
-eosinophils
-basophil
-monocyte
-lymphocyte

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14
Q

what does oxygen transport depend on in the erythrocyte?

A
  • oxygen transport depends on rapid diffusion of oxygen across the red cell’s plasma membranes
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15
Q

what do erythrocytes look like?

A

these cells look like small biconcave disks, presenting a great surface area

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16
Q

what does the lack of nuclei for a red blood cell allow for?

A

lack nuclei (leaves more space in the tiny cells for hemoglobin, the iron-containing protein that transports oxygen)

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17
Q

how do erythrocytes generate ATP?

A

lack mitochondria and generate their ATP exclusively by anaerobic metabolism

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18
Q

true or false, red blood cells have a mitochondria?

A

false, they dont

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19
Q

how many oxygen molecules does a hemoglobin bind to?

A

Each hemoglobin molecule binds up to four molecules of O2

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20
Q

what does hemoglobin bind to?

A

O2 and Nitric oxide

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21
Q

what happens as red blood cells go through the capillary beds of lungs?

A

As red blood cells pass through the capillary beds of lungs oxygen diffuses into the erythrocytes and hemoglobin binds O2 and NO

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22
Q

what happens in the systemic capillaries?

A

In the systemic capillaries, hemoglobin unloads oxygen and it then diffuses into body cells

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23
Q

what does NO do?

A

NO relaxes the capillary walls helping delivery of O2 to the cells

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24
Q

do we have more red or white blood cells?

A

more red

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25
Q

what type of structure is hemoglobin?

A

quaternary

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26
Q

how does NO make blood vessels dilate?

A

relaxes the smooth muscle cells in the blood vessel

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27
Q

what do white blood cells do most of the time?

A

White blood cells spend most of their time outside the circulatory system, patrolling through interstitial fluid and the lymphatic system, fighting pathogens

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28
Q

what are the types of lymphocytes?

A

-B cells
-T cells

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29
Q

what are platelets? where do they orginate from?

A

Platelets are fragments of cells
- they have no nuclei and originate as pinched-off cytoplasmic fragments of large cells in the bone marrow.
- function in blood clotting.

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30
Q

How do lymphocytes and erythrocytes form?

A
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31
Q

what are the two main classes of white blood cells?

A

-granulocytes
-agranulocytes

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32
Q

what are granulocytes?

A

includes Neutrophils, Eosinophils and Basophils

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33
Q

what are agranulocytes?

A

includes Lymphocytes and Monocytes

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34
Q

what’s another word for white blood cell?

A

leukocytes

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35
Q

what’s another word for red blood cell?

A

erythrocytes

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36
Q

true or false, all white blood cells are able to migrate out of blood vessels into surrounding tissue?

A

true

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37
Q

what is the difference between granulocytes and agranulocytes?

A

This classification depends on whether granules can be distinguished in their cytoplasm

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38
Q

what are neutrophils?

A

single multilobed nucleus. They are the commonest type of white blood cell. Neutrophils are born in the bone marrow. They circulate in the blood for 6-10 hours, and then enter the tissues. They are phagocytic and will destroy damaged tissue and bacteria. They are important in inflammatory reactions.

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39
Q

what is the most common white blood cell?

A

neutrophils

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40
Q

what are eosinophils?

A

two lobed nucleus. These cells have large granules - these stain bright red, or reddish-purple.They phagocytose antigen-antibody complexes. A high eosinophil blood count may indicate an allergic reaction.Eosinophils are also important in killing parasitic worms

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41
Q

what are basophils?

A

blue-staining granules and a bilobed nucleus. These cells are involved in immune responses to parasites and also play a role in allergic reactions.

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42
Q

what are lymphocytes?

A

have a small spherical nucleus and abundant dark staining condensed chromatin. There are 2 types. The B-cells develop into plasma cells which make antibodies, T-cells attack viruses, cancer cells, and transplants. Lymphocytes play a major role in the immune response

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43
Q

what are monocytes?

A

a large eccentrically placed nucleus, which is kidney bean shaped.They have abundant cytoplasm, and some fine pink/purple granules in cytoplasm. Monocytes in the circulation are precursors of tissue macrophages that are actively phagocytic. Monocytes circulate in the blood for 1-3 days, and then migrate into body tissues, where they transform into macrophages. They will phagocytose dead cells and bacteria. Monocytes are important in the inflammatory response.

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44
Q

how long do erythrocytes circulate for?

A

Erythrocytes usually circulate for only about 3 to 4 months and are then destroyed by phagocytic cells in the liver and spleen.

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44
Q
A
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45
Q

what happens to old cellular elements of blood after they are destroyed by phagocytic cells in the liver and spleen?

A

Enzymes digest the old cell’s macromolecules, and the monomers are recycled.
Many of the iron atoms derived from hemoglobin in old red blood cells are built into new hemoglobin molecules.

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46
Q

where do erythrocytes, leukocytes and platelets develop from?

A

all develop from a single population of cells, pluripotent stem cells, in the red marrow of bones, particularly the ribs, vertebrae, breastbone, and pelvis

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47
Q

what does pluripotent mean?

A

Pluripotent means that these cells have the potential to differentiate into any type of blood cells or cells that produce platelets.

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48
Q

how can we experimentally treat leukemia?

A

remove pluripotent stem cells from a patient, destroy the bone marrow, and restock it with noncancerous pluripotent cells.

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49
Q

what are the different types of erythrocyte production control?

A
  • If the tissues do not receive enough oxygen, the kidney converts a plasma protein to a hormone called erythropoietin, which stimulates production of erythrocytes.
  • If blood is delivering more oxygen than the tissues can use, the level of erythropoietin is reduced, and erythrocyte production slows
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50
Q

what are the steps of blood clotting?

A

The clotting process begins when the endothelium of a vessel is damaged and connective tissue in the wall is exposed to blood.
(1) Platelets adhere to collagen fibers and release a substance that makes nearby platelets sticky.
(2) The platelets form a plug.
(3) The seal is reinforced by a clot of fibrin when vessel damage is severe.

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51
Q

what is hemophilia?

A

Hemophilia is an inherited defect in any step of the clotting process
- characterized by excessive bleeding from even minor cuts and bruises

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52
Q

what prevents spontaneous clotting?

A

Anticlotting factors in the blood normally prevent spontaneous clotting

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53
Q

what are thrombus? who gets them?

A

Sometimes platelets clump and fibrin coagulates within a blood vessel, forming a clot called a thrombus, and blocking the flow of blood.
These potentially dangerous clots are more likely to form in individuals with cardiovascular disease

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54
Q

what is a heart attack?

A

heart attack is the death of cardiac muscle tissue resulting from prolonged blockage of one or more coronary arteries

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55
Q

what is a stroke?

A

A stroke is the death of nervous tissue in the brain

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56
Q

what is the link between thrombus, strokes and heart attacks?

A

Heart attacks and strokes frequently result from a thrombus that clogs a coronary artery or an artery in the brain

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57
Q

what’s an embolus?

A

thrombus may originate at the site of blockage or it may develop elsewhere and be transported (now called an embolus) until it becomes lodged in an artery too narrow for it to pass

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58
Q

what’s atherosclerosis?

A

growths called plaques develop in the inner wall of the arteries, narrowing their bore.
- the smooth muscle layer of an artery thickens abnormally and becomes infiltrated with fibrous connective tissue and lipids such as cholesterol

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59
Q

what is arteriosclerosis?

A

plaques also become hardened by calcium deposits, commonly known as hardening of the arteries.

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60
Q

true or false, Vessels that have been narrowed are more likely to trap an embolus and are common sites for thrombus formation

A

true

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61
Q

what is angina pectoris?

A

if a coronary artery is partially blocked, a person may feel occasional chest pains, a condition known as angina pectoris.

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62
Q

what is angina pectoris a sign of?

A

This is a signal that part of the heart is not receiving enough blood

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63
Q

what are foam cells?

A

Foam cells are a type of macrophage that localize to fatty deposits on blood vessel walls, where they ingest low-density lipoproteins and become laden with lipids, giving them a foamy appearance

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64
Q

what is hypertension

A

high blood pressure

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65
Q

what does hypertensions promote?

A

promotes atherosclerosis and increases the risk of heart disease and stroke

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66
Q

what does high blood pressure cause?

A

high blood pressure causes chronic damage to the endothelium that lines arteries, promoting plaque formation

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67
Q

what are non genetic factors that cause hypertension?

A

nongenetic factors include smoking, lack of exercise, a diet rich in animal fat, and abnormally high levels of cholesterol in the blood.

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68
Q

true or false, the tendency to develop hypertension and atherosclerosis is inherited

A

true, to a certain extent

69
Q

what is the LDL HDL ratio?

A
  • measure of an individual’s cardiovascular health or risk of arterial plaques can be gauged by the ratio
70
Q

which is the bad cholesterol?

A

LDL

71
Q

what is LDL

A

LDL (low density lipoprotein) is associated with depositing of cholesterol in arterial plaques.

72
Q

what is plaque?

A

Plaque is made up of deposits of cholesterol and other substances in the artery

73
Q

what is HDL?

A

(high density lipoprotein) may reduce cholesterol deposition

74
Q

what does HDL do to reduce cholesterol deposition?

A

scavenges blood for LDL and brings it to liver to metabolize it

75
Q

what is gas exchange?

A

Gas exchange (respiration) is the uptake of molecular oxygen (O2) from the environment and the discharge of carbon dioxide (CO2) to the environment.
- works together with the circulatory system

76
Q

what are the four processes of respiration?

A

respiratory system:
-pulmonary ventilation
-external respiration

circulatory system:
-transport
-internal respiration

77
Q

what is pulmonary ventilation?

A

movement of air into and out of lungs

78
Q

what is external respiration?

A

exchange of O2 and CO2 between lungs and blood

79
Q

what is transport?

A

Transport of O2 and CO2 in blood

80
Q

what is internal respiration?

A

exchange of O2 and CO2 between systemic blood vessels and tissues

81
Q

what are the respiratory surface?

A

lungs

82
Q

how does CO2 and O2 cross the respiratory surface?

A

diffusion

83
Q

what does diffusion require respiratory surfaces to be?

A

1) thin
2) have large areas
3) moist (necessary for gas phase diffusion)

84
Q

where are the capillaries in the lungs?

A

Lungs have a dense net of capillaries just under the epithelium that forms the respiratory surface

85
Q

what do lungs look like?

A

Lungs have a spongy texture and are honeycombed with a moist epithelium

86
Q

how does air enter the body?

A

Air enters through the nostrils and is then filtered by hairs, warmed and humidified, and sampled for odors
- nasal cavity leads to the pharynx, and when the glottis is open, air enters the larynx

87
Q

what is the wall of the larynx reinforced by?

A

wall of the larynx is reinforced by cartilage

88
Q

what is the voice box?

A
  • larynx is adapted as a voicebox in which vibrations of a pair of vocal cords produce sounds
89
Q

how does talking work?

A

sounds are high-pitched when the cords are stretched tight and vibrate rapidly and low-pitched when the cords are less tense and vibrate slowly

90
Q

true or false, the trachea is maintained by rings of cartilage

A

true

91
Q

what does the trachea fork into?

A

forks into two bronchi

92
Q

what do bronchus branch into?

A

each bronchus branches repeatedly into finer and finer tubes, called bronchioles.

93
Q

how is the epithelium lining the major branches of the respiratory tree?

A
  • is covered by cilia and a thin film of mucus.
  • mucus traps dust, pollen, and other particulate contaminants, and the beating cilia move the mucus upward to the pharynx, where it is swallowed.
  • the tiniest bronchioles dead-end as a cluster of air sacs called alveoli.
94
Q

what does the alveolar wall consist of?

A

Single layer of squamous epithelium
Scattered cuboidal cells secrete surfactant and antimicrobial proteins

95
Q

what’s a surfactant?

A

Surfactant is body’s detergent-like lipid and protein complex that helps reduce surface tension of alveolar fluid and this prevents alveolar collapse

96
Q

how does oxygen enter the body? how does carbon dioxide leave the body?

A

Oxygen dissolves in the moist film and rapidly diffuses across the epithelium into a web of capillaries that surrounds each alveolus

Carbon dioxide diffuses in the opposite direction.

97
Q

in the systemic circuit, what is the link between cellular respiration and the systemic circuit?

A

-during cell respiration, we need O2 as a reactant so the capillaries give the tissue this

-the CO2 leaves as its a product of cellular respiration

98
Q

how do humans ventilate?

A

negative pressure breathing

99
Q

what are the lungs enclosed by?

A

double-walled sac (called the pleural sac)

100
Q

what is the pleural sac?

A

The lungs are enclosed by a double-walled sac (called the pleural sac) with the inner layer of the sac adhering to the outside of the lungs and the outer layer adhering to the wall of the chest cavity.

101
Q

what is between the two layers of the pleural sac? what does this allow for?

A

fluid

  • A thin space filled with fluid separates the two layers.
  • Because of surface tension, layers can slide smoothly past each other, but they cannot be pulled apart easily.
    Surface tension couples movements of the lungs to movements of the rib cage
102
Q

what happens during inhalation?

A

Contraction of the rib muscles expands the rib cage by pulling the ribs upward and the breastbone (sternum) outward.
- diaphragm contracts and descends like a piston. The diaphragm is a sheet of skeletal muscle that forms bottom wall of thoracic cavity
- most of the time it contracts involuntarily
- increases the lung volume, and air pressure within the alveoli becomes lower than atmospheric pressure.
- air rushes into the respiratory system.

103
Q

what is the diaphragm?

A

diaphragm contracts and descends like a piston. The diaphragm is a sheet of skeletal muscle that forms bottom wall of thoracic cavity

104
Q

what happens during exhalation?

A
  • the rib muscles and diaphragm relax.
    This reduces lung volume and increases air pressure within the alveoli.
    This forces air up the breathing tubes and out through the nostrils.
  • muscle actions described above are for shallow breathing, when at rest
    During vigorous exercise, other muscles of the neck, back, and chest further increase ventilation volume by raising the rib cage even more.
105
Q

what happens during exhalation during rigorous exercise?

A

During vigorous exercise, other muscles of the neck, back, and chest further increase ventilation volume by raising the rib cage even more.

106
Q

what does surfactant allow for?

A

A substance called surfactant helps the alveoli to stay open for gas exchange. By reducing the surface tension of the fluid on the alveoli, the alveoli remain open even during exhalation.

107
Q

why do premature babies struggle to breathe?

A

Because surfactant is made later in pregnancy, premature babies are lacking a sufficient quantity and this will lead to respiratory distress in the premature newborn

108
Q

why does surfactant allow the alveoli to stay open during expiration?

A

owering surface tension at the air–liquid interface and thus preventing alveolar collapse at end-expiration

109
Q

what is tidal volume?

A

The volume of air inhaled and exhaled with each breath

110
Q

what is the maximum tidal volume called?

A

vital capacity

111
Q

what is the average tidal volume for a human at rest

A

500 ml

112
Q

why is there a residual volume in the alveoli after expiration?

A

some air remains in the lungs, the residual volume, because the alveoli do not completely collapse. needed to keep alveoli open. amount of air that remains after forced expiration

113
Q

what is the inspiratory reserve volume?

A

amount of air that can be inspired forcibly beyond the tidal volume (2100–3200 ml)

114
Q

what is the expiratory reserve volume?

A

amount of air that can be forcibly expelled from lungs (1000–1200 ml)

115
Q

what are respiratory capacities?

A

Combinations of two or more respiratory volumes

116
Q

what is the inspiratory volume?

A

sum of TV + IRV

117
Q

what is Vital capacity?

A

sum of TV + IRV + ERV

118
Q

what is total lung capacity?

A

sum of all lung volumes (TV + IRV+ ERV + RV)

119
Q

what is dead space?

A

does not contribute to gas exchange
Consists of air that remains in passageways
~150 ml out of 500 ml TV

120
Q

what is forced vital capacity?

A

amount of gas forcibly expelled after taking deep breath

121
Q

what is forced expiratory volume?

A

amount of gas expelled during specific time interval of FVC
Healthy individuals can expel 80% of FVC in 1st second

122
Q

what is minute ventilation?

A

: total amount of gas that flows into or out of respiratory tract in 1 minute
Normal at rest = ~ 6 L/min
Normal with exercise = up to 200 L/min
Only rough estimate of respiratory efficiency

123
Q

what happens since the lungs do not completely empty and refill with each breath cycle

A

newly inhaled air is mixed with oxygen-depleted residual air.
- maximum oxygen concentration in the alveoli is considerably less than in the atmosphere.
- limits the effectiveness of gas exchange.

124
Q

what controls the rate and depth of breath?

A

Control centers in the brain regulate the rate and depth of breathing
- most of the time autonomic mechanisms regulate our breathing

125
Q

where are the breathing control centers located in the brain?

A

the medulla oblongata and the pons

126
Q

what does the medulla do to control breathing?

A

the medulla’s center sets basic breathing rhythm, triggering contraction of the diaphragm and rib muscles

127
Q

what does the pons do?

A

aids the medulla via its control center

128
Q

what does the negative feedback inhibition mechanism in the lungs do?

A

negative-feedback mechanism via stretch receptors prevents our lungs from overexpanding by inhibiting the breathing center in the medulla

129
Q

where do cues about the concentration of CO2 come from?

A

cues about CO2 concentration come from slight changes in the pH of the blood and cerebrospinal fluid bathing the brain

130
Q

what does the medulla control center of the brain do?

A

monitors the CO2 level of the blood and regulates breathing activity appropriately

131
Q

why does carbon dioxide lower the pH?

A

Carbon dioxide reacts with water to form carbonic acid, which lowers the pH

132
Q

what happens when the medulla control center registers a slight drop in blood pH?

A

When the control center registers a slight drop in pH, it increases the depth and rate of breathing, and the excess CO2 is eliminated in exhaled air

133
Q

what happens when we hold our breath?

A

-CO2 levels in blood rise
-CO2 combines with water to form carbonic acid
-carbonic acid dissociates to form HCO3- AND H+ (which makes blood more acidic)
-PH sensors detect change and send signal to the brain, forcing the person to breathe

134
Q

true or false, oxygen concentration levels usually have a big effect on breathing

A

false

135
Q

what happens at high altitudes? why does this process work?

A
  • when the O2 level is severely depressed (at high altitudes) sensors in the aorta and carotid arteries in the neck send alarm signals to the breathing control centers, which respond by increasing breathing rate.
  • Normally, a rise in CO2 concentration is a good indicator of a fall in O2 concentrations, because these are linked by the same process - cellular respiration.
136
Q

what is hyperventilation?

A

increased depth and rate of breathing that exceeds body’s need to remove CO2

purges the blood of so much CO2 that the breathing center temporarily ceases to send impulses to the rib muscles and diaphragm

137
Q

what can hyperventilation be caused by?

A

anxiety attacks

138
Q

how can we stop hyperventilation?

A

Treatment: breathing into paper bag increases CO2 levels being inspired

139
Q

control of breathing is only effective when it is matched to…

A

the circulatory system

140
Q

what does gas diffusion depend on?

A

Diffusion depends on differences in partial pressure

141
Q

what is partial pressure?

A

the contribution of a particular gas to the overall total

142
Q

how do gasses diffuse?

A

A gas will always diffuse from a region of higher partial pressure to a region of lower partial pressure

143
Q

what is her atmospheric pressure at sea level?

A

At sea level, the atmospheric pressure = 760 mm Hg

144
Q

is there more O2 or CO2 in the air?

A

a lot more O2

145
Q

what happens during gas exchange in the lungs?

A

Blood arriving at the lungs via the pulmonary arteries has a lower PO2 and a higher PCO2 than the air in the alveoli.
- As blood enters the alveolar capillaries, CO2 diffuses from blood to the air within the alveoli, and oxygen in the alveolar air dissolves in the fluid that coats the epithelium and diffuses across the surface into the blood.
By the time blood leaves the lungs in the pulmonary veins, its PO2 has been raised and its PCO2 has been lowered

146
Q

what happens during gas exchange in the tissues?

A

-In the tissue capillaries, gradients of partial pressure favor the diffusion of oxygen out of the blood and carbon dioxide into the blood.
Cellular respiration removes oxygen from and adds carbon dioxide to the interstitial fluid by diffusion

-After the blood unloads oxygen and loads carbon dioxide, it is returned to the heart and pumped to the lungs again, where it exchanges gases with air in the alveoli.

147
Q

what do respiratory pigments do?

A

Respiratory pigments transport gases and help buffer the blood

148
Q

what would happen if we had no hemoglobin?

A
  • a person exercising consumes almost 2 L of O2 per minute, but at normal body temperature and air pressure, only 4.5 mL of O2 can dissolve in a liter of blood in the lungs.
  • If 80% of the dissolved O2 were delivered to the tissues (an unrealistically high percentage), the heart would need to pump 500 L of blood per minute - a ton every 2 minutes.
149
Q

what is the respiratory pigment?

A

Hemoglobin, the respiratory pigment increases the amount of oxygen in the blood to about 200 mL of O2 per liter of blood.

150
Q

what does hemoglobin consist of?

A

Hemoglobin consists of four subunits, each with a cofactor called a heme group that has an iron atom at its center, found in erythrocytes

151
Q

why do we need respiratory pigments?

A

a person exercising consumes almost 2 L of O2 per minute, but at normal body temperature and air pressure, only 4.5 mL of O2 can dissolve in a liter of blood in the lungs. we need a certain amount of oxygen, but not enough can dissolve into our blood to cater to our needs

152
Q

how much O2 can dissolve into blood at normal body temperature? what does this mean?

A

4.5 mL of O2 can dissolve in a liter of blood in the lungs. this means that the heart would have to pump an unrealistic amount of blood to oxygenate all the tissues

153
Q

does hemoglobin bind reversibly or irreversibly to oxygen

A

reversibly, cause its needs to be able to unload it in all parts of the body

154
Q

true or false, the subunits of the hemoglobin cooperate?

A

true

155
Q

how do the subunits of the hemoglobin cooperate?

A

induces the remaining subunits to change their shape slightly such that their affinity for oxygen increases/decreases:

As O2 binds, Hb changes shape, increasing its affinity for O2 increases

As O2 is released, Hb shape change causes a decrease in affinity for O2

156
Q

what happens as O2 saturation of hemoglobin increases?

A

P02 in blood also increases

157
Q

true or false, the O2 saturation of hemoglobin is very big during exercise?

A

false. its very low (20%)

158
Q

where is the evidence of cooperatively in the dissociation curve?

A

the steep slope

159
Q

what is the link between pO2 and O2 saturation of hemoglobin?

A

even a slight change in PO2 of the tissues causes hemoglobin to load or unload a substantial amount of O2

corresponds to the range of partial pressures found in body tissues

160
Q

what is the Bohr shift?

A

a drop in pH lowers the affinity of hemoglobin for O2, an effect called the Bohr shift.

161
Q

what are the different factors that affect the hemoglobin/O2 bond?

A

-PH of the tissue
-temperature of the tissue

162
Q

why does the PH of the blood affect the bond between the O2 and the hemoglobin?

A

because if the PH is lower, that means we have too much CO2, which means that we need more O2 in the blood, therefore the hemoglobin will release the O2

163
Q

why does the temperature of the blood affect the bond between the O2 and the hemoglobin?

A

At higher temperatures the affinity of hemoglobin for oxygen is decreased. When a tissue is more metabolically active, its temperature will increase. Because the Hb has less affinity for oxygen at these higher temperatures, oxygen will be released to the metabolically active tissue

164
Q

other than transporting oxygen, what else does hemoglobin do?

A

Hemoglobin also helps transport carbon dioxide and assists in buffering blood pH

165
Q

what are the three different ways in which carbon dioxide is transported in the solution?

A
  • 7% of the CO2 released by respiring cells is transported in solution.
  • 23% binds to amino groups of hemoglobin (called carbaminohemoglobin)
  • 70% is transported as bicarbonate ions.
166
Q

what happens to CO2 made by respiring cells?

A

CO2 from respiring cells diffuses into the blood plasma and then into red blood cells, where some is converted to bicarbonate, assisted by the enzyme carbonic anhydrase

167
Q

which enzyme converts CO2 to bicarbonate in the red blood cell?

A

carbonic anhydrase

168
Q

what is the equilibrium between bicarbonate and CO2?

A

The reaction that is catalyzed:
H2O + CO2 = H+ + HCO3-
The reverse reaction is also catalyzed. Carbonic anhydrase solubilizes carbon dioxide gas so we can breathe it out.

169
Q

what happens at the lungs with the bicarbonate equilibrium?

A

At the lungs, the equilibrium shifts in favor of conversion of bicarbonate to CO2

170
Q

What is the relationship between partial pressure and oxygen saturation?

A

As the partial pressure of oxygen increases, the number of oxygen molecules bound by hemoglobin increases, thereby increasing the saturation of hemoglobin.

171
Q

Explain the diagram with the transport/release of CO2 from the erythrocytes

A

human physiology (10 decks)

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