Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

ZOOL 463 > Respiration > Flashcards

Respiration Flashcards

1
Q

respiration

A

exchange of O2 and CO2 between animals and environment

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

what does respiration involve?

A

gas exchange structure (i.e., lungs), circulation and release to tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

series of processes involved in respiration

A

bulk transport, then diffusion, then convection, then diffusion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

what process in respiration do very small animals (especially invertebrates) skip?

A

bulk transport

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

bulk transport AKA

A

ventilation of large volumes of air via a gas exchange structure (lungs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

what happens after bulk transport?

A

diffusion into circulatory system, then diffusion into tissues

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Fick’s law

A

describes rate of diffusion

rate = K x A x ((C2-C1)/L)
K = constant, A = SA, C = concentration (2 = lungs; 1 = blood), L = distance of diffuson

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

how can you increase diffusion rate?

A

increase surface area, decrease distance of diffusion, increase concentration gradient (increase concentration in lungs or decrease concentration in blood)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

how are lungs adapted to increase diffusion rate?

A

very high surface area, very thin tissue (decreases distance), and constant ventilation to keep concentration gradient high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

lung structure in order

A

trachea > bronchi > bronchioles > respiratory bronchioles > alveolar ducts > alveolar sac > alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

conducting zone

A

bronchioles, bronchi, trachea

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

respiratory zone

A

where respiration occurs

respiratory bronchioles, alveolar ducts, alveolar sac, and alveoli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

trachea

A

tube in throat - linked to pharynx in humans

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

respiratory bronchioles

A

special bronchioles where gas exchange can occur

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

what role does the conducting zone play?

A
  • has mucus escalator - goblet cells secrete mucus; cillia beat upward to move mucus to pharynx (then swallowed)
  • captures particulates (like dust)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

what happens in cystic fibrosis

A

mucus escalator is compromised - mucus thickened, which obstructs airways and affects respiratory system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

features of the respiratory zone (specifically alveoli)

A

super thin tissue (0.2-15 microns), huge surface area (1 human lung = 250 million alveoli, 65 sq m), thin and coated with watery solution (act like bubbles - high surface tension)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

pleural sac/cavity

A

fluid-filled sac that encompasses lung and provides lubrication for smooth movement and holds lungs open

2 membranes (one by lungs - visceral and one by chest wall - parietal)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

pleurisy

A

inflammation of pleural sac membrane due to infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

diaphragm

A

muscle at base of lungs - connected to pleural sac but not lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

diaphragm shape when relaxed vs contracted

A

relaxed = arched (lengthens when relaxes)
contracted = flattened (shortens when contracts)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

chest wall

A

rib cage, sternum, thoracic vertebrae, connective tissue, intercostal muscles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

intercostal muscles

A

in between ribs; 2 sets: external and internal (antagonistic muscles)

connected to pleural sac (along with ribs)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

external intercostal muscles

A

outside of ribcage - function is to lift ribcage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

internal intercostal muscles

A

inside ribcage - function is to depress ribcage

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

at rest, the lung has a tendency toward collapse - why?

A
  • of weight of chest cavity
  • elasticity of lung tissue (always in a slightly stretched state - tendency of recoiling)
  • surface tension in alveoli (has tension pulling inwards - collapsing while air inside has outward force)
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

collapse is opposed by

A

pleural sac and production of surfactant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

how does the pleural sac oppose collapse?

A

fluid-filled (think about a syringe, liquids cannot be compressed or expanded) and drags lung along with any force applied on it

pleural sac is attached to diaphragm and ribs hold lung open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

how does the production of surfactant oppose collapse?

A

detergent-like substance secreted by cells in alveoli - decreases surface tension in alveoli so they stay open

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

why does surfactant decrease surface tension

A

cannot blow bubbles with just water (too high surface tension) - need soap to decrease it

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

what is the release of surfactant triggered by?

A

stretch (inhaling)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

why is surfactant important for mammalian newborns?

A

first breath of baby is to break open alveoli - lots of surfactant is produced right before birth to reduce surface tension so baby can inflate lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

what role does the ventilator play for premature babies?

A

holds lungs open + supplies artificial surfactant

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
34
Q

infant respiratory distress syndrome

A

baby is born before surfactant production begins (first breath is unable to open lungs due to high surface tension)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
35
Q

what is the consequence of the opposing collapse in the lungs?

A

there’s always some air in the lungs (retention of stale air)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
36
Q

3 main parts of the breathing cycle

A

tidal ventilation, inhalation, exhalation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
37
Q

tidal ventilation

A

like a tide = air enters and exit on same path

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
38
Q

what happens during inhalation?

A
  1. contract external intercostals and diaphragm, expansion of chest cavity
  2. pulls on pleural sac and generates negative pressure below ambient in pleural fluid
  3. fluid follows pleural sac, pulls on lungs, lungs expand, negative pressure in lung so air is sucked in
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
39
Q

what happens during exhalation at rest?

A

exhalation is completely passive - weight and elastic recoil makes lung volume smaller, positive pressure inside lung so it pushes air out

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
40
Q

what happens during exhalation during activity?

A

same as rest (positive pressure in lung) PLUS contract internal intercostals, contract muscles of abdomen = helps reduce lung volume and increase positive pressure further, expelling air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
41
Q

what is a limitation of mammalian lung anatomy?

A

dead space

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
42
Q

2 types of dead space

A

anatomical (structural) and alveolar (functional)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
43
Q

anatomical dead space

A

arises due to conducting structure of lung - volumes of air in conducting zone don’t contribute to gas exchange and lungs are open all the time (stale air mixes with fresh air reducing effectiveness)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
44
Q

alveolar dead space

A

not all alveoli are receiving air or blood all the time (so they don’t contribute physiologically)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
45
Q

physiological dead space

A

sum of anatomical + alveolar

very significant - normal resting breath = 350 mL fresh air in inhale but lung capacity is 3 L

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
46
Q

what is the consequence of dead space?

A

significantly less O2 in air inside lung than in atmospheric air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
47
Q

what is the driving force of gases?

A

partial pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
48
Q

why is partial pressure used?

A

gas diffusion into a liquid is more accurately described by partial pressure than concentration gradient

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
49
Q

what moves O2 into blood and CO2 out of blood?

A

partial pressure = driving force!

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
50
Q

partial pressure

A

portion of total pressure that a single gas is exerting

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
51
Q

sea level atmospheric air pressure

A

760 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
52
Q

partial pressure of O2 at sea level

A

0.21 x 760 = 160 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
53
Q

partial pressure of CO2 at sea level

A

0.03 x 760 = ~0 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
54
Q

partial pressure is dependent on

A

altitude

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
55
Q

atmospheric air pressure in Calgary

A

667 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
56
Q

partial pressure of O2 in Calgary

A

0.21 x 667 = 140 mmHg

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
57
Q

partial pressure of O2 in lungs is lower than atmospheric because

A

large presence of water vapour in lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
58
Q

higher pp of O2/lower pp of CO2 in atmospheric air than lungs does what?

A

drives O2 into and drives CO2 out of lungs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
59
Q

what does the solubility of O2 and CO2 depend on?

A

dissolvability in water depends on:
1. partial pressure of gas
2. temperature
3. salinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
60
Q

how does partial pressure affect solubility?

A

higher pressure gradient means more dissolved gas - gas dissolves until pp in fluid = pp in air

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
61
Q

how does temperature affect solubility

A

cold water means more gas dissolved

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
62
Q

how does salinity affect solubility?

A

less salt means more gas can dissolve

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
63
Q

is O2’s partial pressure higher or lower at the top of Mt. Everest than in Calgary?

A

lower

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
64
Q

Assuming constant pp, is there more O2 in salt or fresh water at the same temperature?

A

fresh water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
65
Q

Assuming constant pp, is there more O2 in a Petri dish containing fresh water or a plasma sample at same temperature?

A

fresh water - plasma = H2O based solution but has higher salinity

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
66
Q

Assuming constant pp, is there more O2 in hot or cold tap water?

A

cold tap water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
67
Q

comparative ventilation

A

gas exchange surface area (lungs, alveoli, gill tissue, etc.) matches O2 demand

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
68
Q

as body size increases, how does gas exchange surface area change?

A

also increases

bigger animals have more cells because they have a greater demand for cellular respiration and O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
69
Q

how does gas exchange surface area differ in endotherms and ectotherms?

A

more SA in endotherms (i.e., frog and mouse may have same body weight but gas exchange SA higher in mouse)

heat regulation requires more energy and O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
70
Q

bird ventilation steps

A

inhale #1 = to posterior air sac (expands)
exhale #1 = to rigid lungs and some back to main airway
inhale #2 = to anterior air sac
exhale #2 = out of body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
71
Q

what is one difference between bird and mammalian lungs?

A

bird lungs are rigid - do not change in shape or size

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
72
Q

why do birds need to extract more O2 than mammals?

A

because they fly which requires lots of O2

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
73
Q

do birds have tidal ventilation?

A

no - one way continuous flow (doesn’t go out/in on the same path)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
74
Q

does bird ventilation have dead space?

A

no - stale air and fresh air do not mix (the air that goes back to main airway from posterior air sac is still fresh!)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
75
Q

insect ventilation systems tend to involve

A

a network of gas-filled tubes (no lungs)

76
Q

what is the network of gas-filled tubes in insects called?

A

tracheal system

77
Q

how does fresh air enter the tracheal system in insects?

A

through pores of body surface or aquatic insects may have gill-like structures or hollow hairs

78
Q

invertebrates that don’t fly use what for gas exchange?

A

diffusion (no lungs or tracheal system)

79
Q

why are insect ventilation systems so specialized?

A

flying is energetically costly - air movement through passive diffusion (no active pumping)

80
Q

what are some challenges that might make breathing hard for aquatic organisms?

A

water has higher density than hair, O2 is less soluble in water than air (low O2 content), water is viscous and heavy (hard to move)

81
Q

gills

A

external filamentous tissues used for gas exchange

82
Q

gills can be either

A

fully externalized (no protective structure around them) or covered gills (external to body cavity but have hard structure covering them)

83
Q

fish gills have a specialized type of flow

A

countercurrent (opposite)
blood: flows posterior to anterior
water: flow anterior to posterior

84
Q

flow of water in/out fish body

A

active pumping into mouth, over gills and out through operculum opening (anterior to posterior)

85
Q

how does countercurrent flow affect O2 pickup capabilities?

A

higher efficiency of extraction - consistent concentration gradient exists along whole length of the gill

86
Q

what type of flow do mammalian lungs use?

A

concurrent (same direction)

may have some limitations but gets the job done (air also has more O2 than water)

87
Q

what type of flow do bird lungs use?

A

cross-current (specialized flow system) - better than concurrent but not as good at countercurrent

flow of respiratory medium (air) is almost perpendicular to flow of blood (like a grid)

88
Q

why are ventilation and perfusion matched?

A

too much movement = waste of energy while moving too little = not meeting energy demands

89
Q

perfusion

A

blood flow

90
Q

V/Q ratio

A

V = ventilation; Q = perfusion (volumetric flow rate)
e.g. 1:1 = 1 unit of air per 1 unit of blood; 2:1 = 2 units of air per 1 unit of blood

91
Q

V/Q ratio of mammals (whole lung)

A

1:1

92
Q

V/Q ratio of fishes (whole gill)

A

~10 (10 units of water:1 unit of blood)

93
Q

challenge for fish in terms of V/Q

A

water has less O2 than air and fish blood carries half the amount of O2 as mammalian blood (not good at carrying O2)

2 opposing problems

94
Q

how do fishes overcome lower solubility of O2 in water?

A

increase ventilation (increase V - send more water), reduce blood flow (decrease Q)

95
Q

how do fishes overcome their blood carrying less O2?

A

reduce water flow (decrease V), send more blood (increase Q)

96
Q

net effect of fish overcoming its 2 challenges of less O2 in water and in blood

A

an overall increase V and decrease Q to make V/Q ratio ~ 10 (10 units of water for 1 unit blood)

97
Q

what is the underlying issue of low V/Q

A

too much blood (Q too high) and not enough air (V too low)

98
Q

how does the mammalian lung correct for too much blood - high Q?

A

too much CO2 present
smooth muscles in alveolar duct are sensitive to CO2 increases - triggers them to relax and opens alveolar duct to let air carry CO2 away

99
Q

how does the mammalian lung correct for too little air - low V?

A

too little O2 present
vascular smooth muscle in capillaries are sensitive to O2 decreases - contract when O2 low (constricts blood vessels and reduces blood flow Q)

100
Q

what does decreased O2 usually lead to in smooth muscle?

A

relaxation - but in vascular smooth muscle, causes constriction to decrease Q since V is so low

101
Q

at altitude, how does the partial pressure of O2 change?

A

decreases

102
Q

at altitude, how does blood flow change?

A

decreases

103
Q

pulmonary edema

A

happens at high altitudes (low blood flow) where constriction raises blood pressure in lung and causes rupture of capillaries
also drives fluid out of vessels and into alveoli, reducing gas exchange abilities

104
Q

what is the problem with the dissolved O2 levels in our blood?

A

not enough to supply tissues

105
Q

metabolic demand at rest (resting metabolic rate, VO2 rest)

A

consume 250 mL O2/min

106
Q

blood flow at rest

A

heart circulates 5 L blood/min

107
Q

blood plasma O2 solubility

A

3 mL O2/L blood (really low solubility)

108
Q

how much O2 does blood plasma deliver?

A

5 L blood/min x 3 mL O2/L = 15 mL O2/min

(less than our VO2 rest = 250 mL O2/min)

109
Q

steps of oxygen getting taken up by blood + Hb

A
  1. High PO2 in lung causes O2 to dissolve in the plasma (low PO2 in blood)
  2. Raise PO2 of blood with dissolution - drives Hb to pick up blood
  3. O2 binding to Hb reduces blood PO2
  4. Low blood PO2 now lets more O2 dissolve (loops back to step 1)
110
Q

oxygen dissociation curve

A

shows relationship between amount of O2 dissolved in body and held by Hb

111
Q

what are the axes labels on an oxygen dissociation curve?

A

y-axis = % saturation of Hb (100% = 4 O2, 50% = 2 O2, etc.)
x-axis = PO2

112
Q

for Hb, what is the shape of the oxygen dissociation curve?

A

s-shaped - shows cooperativity
increases O2 affinity as more O2 binds

113
Q

for Mb, what is the shape of the oxygen dissociation curve?

A

square-root (curved) - no cooperativity

only 1 O2 binding site

114
Q

Mb

A

myoglobin - supplies O2 to muscles

115
Q

lungs on oxygen dissociation curve

A

at plateau - some wiggle room to change PO2 without affecting O2

116
Q

tissues on oxygen dissociation curve

A

at increase (slope) - change in PO2 changes saturation

117
Q

exercising muscle uses O2; what does this do to the PO2 in this tissue?

A

lowers PO2 (decrease due to decrease in O2 saturation)

118
Q

fresh blood arrives to exercising muscle; how does Hb respond to the decreased PO2 in that tissue?

A

decrease in saturation of O2 = Hb will release its O2

119
Q

how is affinity for Hb for O2 measured?

A

P50

120
Q

P50

A

partial pressure needed to saturate Hb to 50%

121
Q

how does affinity for O2 changes with P50?

A

higher the P50, the lower the affinity

(need to work harder to get Hb to pick up oxygen)

122
Q

myoglobin vs hemoglobin affinity for O2

A

higher affinity in Mb (lower P50) - O2 preferentially binds to Mb

123
Q

Hb affinity for O2 is reduced by

A

heat, presence of organic phosphates (ATP), lowered pH, increase in CO2

properties of muscle use (exercise)

124
Q

Bohr shift

A

right shift in Hb affinity for O2 based on pH (more acidic - pH<7.4)

125
Q

reverse Bohr shift

A

left shift in Hb affinity for O2 based on pH (more basic - pH>7.4)

126
Q

Hb affinity for O2 at lower pH

A

lower (higher P50) when acidic

127
Q

Hb affinity for O2 at higher pH

A

higher (lower P50) when basic

128
Q

why does a lower pH cause lower Hb affinity for O2?

A

more acidic conditions indicate increased CO2, so encourages Hb to release O2

129
Q

Root shift

A

down shift in Hb affinity for O2 based on pH

130
Q

which is given more priority: Bohr shift or Root shift?

A

Root shift (down shift)

131
Q

what happens with a root shift?

A

max out at <100% saturation

132
Q

which animals can root shift?

A

some animals like fish (NOT mammals)

133
Q

mechanism for root shift in fish

A

fill swim bladder - secrete lactic acid into tissues near swim bladder, causes root shift and helps force Hb to release O2 which gets shuttled to swim bladder

some fish do this in eye + brain - keeps metabolism higher here for higher function

134
Q

after exposing a respiratory pigment to H+, you find that its P50 for O2 has increased; how has its affinity for O2 changed?

A

decreased affinity

135
Q

name 4 ways Hb’s affinity for O2 can be reduced

A

heat, presence of H+ ions, organic phosphates, CO2

136
Q

thinking about the V/Q ratio at the whole-lung scale, if we observe that V is increasing, what is happening?

A

V = ventilation - breathing faster

137
Q

after CO2 dissolves in water, what happens?

A

enter carbonic acid reaction

138
Q

carbonic acid reaction

A

CO2 + H2O ⇔ H2CO3 (carbonic acid) ⇔ H+ + HCO3- (bicarbonate) ⇔ 2H+ + CO3(2-) (carbonate)

139
Q

what catalyzes the carbonic acid reaction?

A

carbonic anhydrase (enzyme)

140
Q

which is favoured more in the carbonic acid reaction: bicarbonate or carbonate ion?

A

bicarbonate (yields 1 H+)

141
Q

3 places CO2 can be found in blood

A

dissolved (20x more soluble than O2), bound to Hb, tied up in a bicarbonate

142
Q

where is the majority of CO2 in blood found?

A

tied up in bicarbonate (70-80%)

143
Q

what type of CO2 counts toward PCO2?

A

dissolved CO2 (~10% of CO2)

144
Q

Haldane effect

A

Hb with less O2 has higher affinity for CO2 and H+ so Hb carries more CO2 and H+

145
Q

chloride shift

A

rapid anion exchange protein exchanges bicarbonate for chloride ion (moves bicarbonate ion out of the RBC)

146
Q

what range of pH do we tolerate?

A

7.0-7.6 (blood is usually ~7.4)

147
Q

methods for regulating blood pH

A

use bicarbonate, get rid of H+, adjust ventilation

148
Q

how do we use bicarbonate to regulate blood pH?

A

shift carbonic acid reaction toward CO2 + H2O (shift left) to use up extra H+

kidneys: expel bicarbonate (reaction shifts right), causing increase in H+ and lowers pH

149
Q

how is H+ regulated to regulate blood pH?

A

kidneys: expels H+, raises pH
proteins: “soak up” H+ (including some H+ on Hb) to raise pH - very effective

150
Q

difference between changing pH in blood vs water

A

500,000x more H+ required to changes pH of blood than water

151
Q

most of blood pH regulation is through

A

breathing (adjusting ventilation)

152
Q

how do we adjust ventilation to regulate blood pH?

A

respiratory alkalosis or respiratory acidosis

153
Q

respiratory alkalosis

A

breathe faster - increases V which increases V/Q ratio which decreases CO2 in blood; this uses up H+ in carbonic acid reaction (to replenish CO2) and raises pH

154
Q

respiratory acidosis

A

breathe slower - decreases V and lowers V/Q ratio which causes build-up/backlog of CO2, pushing carbonic acid reaction toward H+ and lowers pH

155
Q

how else do aquatic animals regulate blood pH?

A

exchange ions over skin and gills

156
Q

how are ions exchanged in aquatic animals to regulate blood pH?

A
  1. active H+ pumps - use ATP to move H+ outside of body (raises pH)
  2. pump bicarbonate out through chloride shift and carbonic acid reaction shifts right to replenish + increases H+ (lowers pH)
157
Q

2 categories of sensors for respiratory gases

A

peripheral sensors (PNS) and central sensors (CNS - monitor cerebrospinal fluid)

158
Q

what is sensed to control respiratory gases?

A

O2 and pH (proxy for CO2)

159
Q

3 major sensors in mammals

A

aortic arch, carotid arteries, medulla

160
Q

aortic arch

A

peripheral sensor, shuttle blood to body from heart - sense O2, blood volume and hematocrit

161
Q

carotid arteries

A

peripheral sensor, supplies blood to brain - sense O2, blood volume and hematocrit

162
Q

medulla

A

central sensor, at base of brain leading to spinal cord - senses pH in CBSF

163
Q

why do air-breathing animals primarily monitor pH?

A

always have 21% O2 in air, O2 is consumed and CO2 is produced at same rate, both are moved using the lungs at the same time
SO if we monitor for CO2, we end up with right amount of O2

164
Q

role of O2 sensors in air-breathing animals

A

back-up plan - we don’t use these sensors in healthy, normal conditions unless O2 levels get very low

165
Q

water-breathing animals primarily monitor

A

O2 - peripheral sensors

166
Q

air-breathing animals primarily monitor

A

pH (CO2) - central sensors

167
Q

why do water-breathing animals primarily monitor O2?

A
  • very little O2 in water
  • O2 levels in water vary a lot (e.g. temp affects solubility)
    SO must adjust breathing to compensate for changes in O2
168
Q

to control respiratory gases, how do we respond to change?

A

increase or decrease ventilation

169
Q

how does your breathing changes when you start to exercise (ways mammals change V)?

A

breathe faster or breathe deeper

170
Q

hypoxia

A

low O2 in tissues - a form of respiratory stress

171
Q

why is hypoxia rare for air-breathers under normal function?

A

tons of O2 present in air

172
Q

causes of hypoxia

A

breathing very slowly, lung diffusion limitations, altitude, suffocation (not enough O2 in air), impaired ability to carry O2 in blood

173
Q

what are some examples of lung diffusion limitations that could lead to hypoxia?

A

infant respiratory distress syndrome, pulmonary edema, emphysema (loss of alveolar SA, stiff lungs)

174
Q

what would impair ability to carry O2 in blood?

A

severe blood loss, anemia, CO poisoning

175
Q

why is hypoxia more common in water-breathers

A

limited O2 levels in water

176
Q

how are the low levels of O2 in water dealt with by water breathers?

A

increase V, grow more gill tissue (increase SA), metabolic depression (reduce BMR to reduce O2 consumption)

177
Q

how is respiratory stress dealt with by diving mammals?

A

some hypoxic tissues during dives - can prioritize which tissues get O2

178
Q

how is respiratory stress dealt with by carps (goldfish)?

A

they can tolerate anoxia (no O2) via a fermentation system where they produce lactic acid and convert it to alcohol which is diffused out of gills

179
Q

O2 demands varies based on

A

activity level

180
Q

how can O2 demand higher than the VO2 max (aerobic MR) be met?

A

by supplementing with anaerobic metabolism to reach the highest activity level

181
Q

O2 needs during submaximal activity (<VO2 max) - e.g. easy job

A

real O2 consumption lags behind activity’s O2 demand

182
Q

O2 deficit on O2 demand vs time graph

A

takes time for body to ramp up and supply O2 to match demand

183
Q

EPOC

A

excessive postexercise oxygen consumption - consuming more O2 than activity demands (recovering from fatigue)

184
Q

how does EPOC change with activity

A

increases - longer with higher level of activity (need more time to cool down)

185
Q

why is our O2 demand non-zero at rest?

A

we have non-zero MR (BMR)

186
Q

O2 needs during supermaximal activity (at >VO2 max)

A

prolongs EPOC and O2 demand is supplied by anaerobic metabolism

ZOOL 463 (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions