Exam 3: Ch 13 Notes Flashcards Preview

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Flashcards in Exam 3: Ch 13 Notes Deck (114)
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1
Q

gas exchange challenges

A

SA:Vol ratio

need O2 for cellular respiration

need to dump O2 from cellular respiration

2
Q

does an amoeba need gills?

A

no, it has a high surface area to volume ratio

3
Q

atmosphere makeup

A

78% N2

21% O2

9% other

0.3% CO2

4
Q

gas exchange must meet ______ specific demands

A

tissue specific demands

5
Q

problem… where do you live?

A

sea level

altitude

in water

6
Q

in the water, O2 is only available…

A

1/30th of atmosphere

dissolves from atmosphere

produced from photosynthesis

7
Q

water in diff salinities/temps

A

fresh

salt @ 30 degrees 4.34 ml O2/L

salt @ 15 degrees 5.75 ml O2/L

8
Q

water has layers

A

salinity and temp restrict O2 movement

less diffusion

9
Q

how to max diffusion

A

large surface area

minimize distance to diffuse

maximize concentration gradient –> remove boundary layers w/ blood flow

10
Q

hemoglobin increases

A

carrying capacity of blood

11
Q

how do we increase carrying capacity more

A

RBC increase production of EPO

plasma

doping: 1 pt of blood –> spin –> give RBC back “treacle” viscous blood

12
Q

ice fish don’t have a _______ pigment

A

respiratory

low temp –> more O2 dissolved

temp conformer so low temp = low metabolic rate (less O2 demand)

increased blood volume and cardiac output

13
Q

hemoglobin structure

A

2 dimers a,b a2,b2 4 subunits each binds O2

14
Q

Hb + O2 vs. Hb by itself

A

oxyhemoglobin; deoxyhemoglobin

15
Q

Hb is better at binding..

A

carbon monoxide 200x

displaces O2

no detection system

16
Q

sickle cell anemia

A

Hb clumps, distorts RBC

lower O2 carrying capacity

RBC get stuck in capillaries

resistance to malaria

17
Q

myoglobin

A

muscles 1 subunit

no subunit cooperativity

not as well tunes

18
Q

Hb + O2 cooperative binding

A

sigmoidal curve

good at binding O2 in regions w/ high pO2

bad at binding O2 in regions w/ low pO2

this allows Hb to release O2 in tissues w/ low O2

19
Q

how is Hb tuned

A

more release at partial pressures that are experienced in metabolic tissues

20
Q

Bohr effect

A

more acidic conditions = less O2 bound to Hb

ex. 30mmHg pH 7.4 = 30% saturation

pH 7.2 = 15% saturation

21
Q

what conditions wound you find in exercising muscle

A

more acidic

less O2, more CO2

higher temp

all cause Hb to release more O2

22
Q

Hb has a changing affinity for O2 depending on

A

conditions of surrounding tissue

23
Q

developmental changes of Hb

A

different Hbs

fetal Hb binds O2 better, better transport of maternal O2 –> fetus

24
Q

CO2 transport

A

oxygenated blood has less CO2 carrying capacity

deoxygenated blood has more CO2 carrying capacity

25
Q

CO2 transport in peruvian, tibetan, and kenyan people

A

lower CO2 binding Hb

increased RBC, Hb, NO

more heart capacity

26
Q

andean populations

A

increased RBC + Hb

many unsaturated RBC

viscous blood

27
Q

himalayan population consists of which two groups

A

tibet and nepal

28
Q

himalayan populations CO2 transport

A

O2 sat lower than sea level

high levels of NO (240x)

vasodilator, blood vessel relaxation in lungs (wider for blood flow)

29
Q

himalayan populations breathe…

A

deeper and faster

EPAS1 - monitors O2 levels

prevent overproduction of RBC

30
Q

kenyan populations

A

increased rate of O2 transfer from alveoli to blood

Hb levels and O2 saturation same as sea level

31
Q

major things that Hb binds

A

O2

H+

CO2

32
Q

both __ and __ compete w/ O2 for Hb binding

A

H+, CO2

33
Q

CO2 to HCO3- and H2CO3 ratios

A

CO2:H2CO2 1000:1

CO2:HCO3- 1:20

34
Q

most CO2 in blood is transported by…

A

HCO3-

35
Q

carbamino Hb

A

protein-NH2 + CO2

36
Q

can deoxygenated blood carry more CO2 than oxygenated blood?

A

yes

37
Q

CO2 pathway in blood

A

CO2 into blood –> RBC have high carbonic anhydrase –> HCO3- out, Cl- in via band III passive transporter protein

38
Q

does muscle produce CO2?

A

yes

Hb deoxygenation binds H+ –> increases HCO3- production to buffer pH change

39
Q

CO2 in lungs

A

Hb oxygenation –> H+ release –> HCO3- –> H2CO3 –> released CO2 + H2O

40
Q

carbonic anhydrase design tweak

A

in epithelial cells carbonic anhydrase speeds up HCO3- –> CO2

41
Q

if deoxygenated Hb binds H+, reaction shifts to the _____ and _____ CO2 converted

A

right, more

42
Q

reasons for O2 delivery

A

reduced pO2

H+ competed for Hb binding

CO2 competes to form carbamino Hb

43
Q

is there gas transfer in cartilage?

A

no

44
Q

cystic fibrosis

A

mutated Cl- transporter, thick mucus not removed

45
Q

terminal bronchioles are made of

A

smooth muscle

46
Q

asthma

A

inflammation

smooth muscle contraction

47
Q

growth of alveoli

A

birth to 8 yrs old increase # of alveoli

8 to adult increase size of alveoli

environment dependent

48
Q

at rest human tidal volume is…

A

10% of max

49
Q

why do amphiuma breath 1/hr

A

vulnerable at surface

tidal volume 50% of max

during 1hr, pO2 volume changes

pCO2 stable –> lost through skin

50
Q

blood supply to lung

A

apex lower

base higher

51
Q

if there is low O2 in a region of lung what happens

A

vasoconstriction to that region shifts more blood to better functioning regions

“hypoxic” pulmonary vasoconstriction involves ion channels

52
Q

amphiuma live in ____ O2 water

A

low

heart rate is steady

intake is 50% max lung capacity

O2 levels fluctuate between breaths

CO2 levels remain constant –> released across skin

53
Q

lung capillaries

A

sheet w/ film of blood between 2 surfaces

if you are vertical, less pressure so thinner sheet

54
Q

is pulmonary BP lower than systemic?

A

yes

55
Q

what channels are in capillary membranes

A

K+

inhib –> depol –> open voltage-gated Ca2+ channels –> influx of Ca2+ –> smooth muscle contraction, vasoconstriction

56
Q

at altitude you get chronic ______

A

hypoxia

low O2 region in lung –> vasoconstriction

low O2 in muscles –> vasodilation

57
Q

frog pulmonary cutaneous system

A

gas exchange to lungs/skin

non-rhythmic breathing

breathing increases blood flow to skin

systemic blood flow is constant

58
Q

human diaphragm and ribcage

A

diaphragm down and ribcage elevated

lowers pressure in lungs so air can come in

breathe in and out incomplete gas exchange: residual air

59
Q

bird breathing

A

air sacs change volume

lungs –> gas exchange

“flow through” system - 2 cycles of air to pass through

60
Q

alveolar (bag) surface

A

moistness causes surface tension

lipoprotein surfactants reduce surface tension for more efficient breathing

61
Q

premature babies don’t produce ________

A

surfactant

causes positive pressure

add surfactants

inject mom w/ cortisol (type II cells mature)

62
Q

H2O is dense, 1/30th of O2 content of ____

A

air

slower diffusion (10,000x)

gills –> unidirectional flow, need higher flow rate

63
Q

gill breathing

A

inspiration –> operculum closed –> H2O in mouth flows across gills

lower flow of mouth

expiration –> mouth closed, mouth flow raised

64
Q

counter current system

A

more efficient exchange across whole length of gill surface

diffusion gradient maintained

H2O in one direction, blood in opposite direction

65
Q

counter current system works if…

A

fast H2O flow

less loss of O2

gradient maintained

66
Q

ram ventilation

A

fish that constantly swim w/ mouths open

67
Q

Va / Q ~ 1 humans

Va / Q ~ 10 fish

A

Va = rate of ventilation

Q = rate of diffusion

higher rate of H2O flow over gills, less O2 dissolved in H2O

68
Q

respiratory center receptors

A

chemoreceptors

mechanoreceptors (lung-stretch)

69
Q

chemoreceptors

A

sense CO2, pH, O2

aortic bodies: CO2

carotid bodies: pH

70
Q

lung-stretch receptors

A

inflate lungs sensed –> inhibit inspiration center via vagus nerve

71
Q

central pattern generator

A

depth and amplitude

72
Q

rhythm generator

A

frequency

73
Q

inspiration center neurons

A

phrenic nerve

respiratory motor neurons

lower pressure in lungs

air intake

74
Q

increased alveolar pCO2 leads to…

A

increased phrenic nerve activity –> increased inspiration

75
Q

in mammals, __ levels are the major driver of changes in inspiration

A

CO2 levels

alveoli stretch receptors activated –> early shut off of phrenic nerve activity

76
Q

carotid body

A

better detector of pH and CO2 than O2

77
Q

aortic body

A

better detector of O2 than CO2 or pH

78
Q

medulla

A

pH, CO2 in CSF

79
Q

carotid body is activated by

A

high CO2

low pH, O2

increases firing rate –> respiratory center –> increased breathing

80
Q

structure of carotid body

A

vessel network and glomus cell detector release nt

nt goes to neurons –> respiratory center and other glomus cells

decreased pO2 –> increased breathing rate

81
Q

medulla mechanism

A

stimulation is needed –> artificially low body Co2 –> reduced breathing

82
Q

why CSF medulla?

A

increased blood CO2 –> high H+ –> buffered by Hb

CSF has no RBC so no buffering, more sensitive indicator

high blood CO2 –> high CSF CO2 –> lower CSF pH –> higher breathing rate

83
Q

effect of higher breathing rate

A

more release of CO2

pH returns to normal

84
Q

in fish, __ levels are the major driver (sensors in gills) of changes in inspiration

A

O2 levels

CO2 more soluble in H2O so O2 is limiting factor

85
Q

at altitude, pulmonary edema

A

fluid in lungs makes shortness of breath crackling sounds

how? low O2 –> increased breathing rate, pulmonary BP, permeability of muscular epithelium

86
Q

O2 levels vary in H2O

A

salt vs fresh

warm vs. cold

photosynthesis

O2 using organisms

mixing from surface

87
Q

fish adapted to cope w/ wide range of pO2

A

stop feeding

lower metabolism

less swimming

more gill ventilation

move to cooler H2O

less breeding

88
Q

humans @ altitude

A

low pO2 carotid/aortic receptors

higher ventilation and CO2 elimination

lower pCO2 in blood to raise pH in blood/CSF to reduce ventilation

89
Q

short-term human adaptation

A

reset trigger levels

90
Q

long-term hypoxia

A

gradual increase in ventilation

systemic vasodilation

higher cardiac output

up to 33% increase in blood volume

91
Q

low blood CO2 levels lead to

A

high pH

increase Hb affinity for O2

92
Q

good/bad of increased Hb affinity for O2

A

good: increased O2 uptake in lungs
bad: less O2 deposition in tissues

93
Q

body’s response to increased Hb affinity for O2

A

more DPG production

binds to deoxyhemoglobin to reduce affinity for O2

more O2 released

94
Q

hypoxia leads to _____ production

A

HIF-1 (erythropoetin) RBC production

vascular endothelial growth factor (VEGF) more blood vessel growth capillaries

95
Q

diving animals have __ storage

A

O2

96
Q

diving animals have __ storage

A

O2 in lungs, blood, myoglobin

O2 –> CNS shift in circulation (less O2 to gut, muscles) –> myoglobin to store O2

97
Q

during a dive…

A

HR slows, reduced swimming (gliding), reduced metabolic rate

98
Q

exhalation at the beginning of a dive…

A

reduces buoyancy

less gas in alveoli –> less gas transfer at depth –> reduces pGases –> no embolisms if rapid ascent

99
Q

humans at birth

A

aquatic to air breathing (hypoxia)

early postnatal tissue is hypoxia resistant

100
Q

10m = _atm

A

1atm

surface 1atm 1L –> 10m, 2atm 500ml

101
Q

buoyancy control

A

swim bladder

made of mostly O2, relatively gas impermeable structure

high pO2

H2O/blood have low pO2

102
Q

swim bladder challenge

A

O2 in against conc gradient

localized high concentration of O2 in blood –> diffuses into bladder

103
Q

mechanism of diffusion into swim bladder

A

highly vascularized artery/vein –> closed apposition –> counter current system

104
Q

cells in swim bladder

A

patch of foregut cells that are gas impermeable

slow leak

105
Q

specialized structures of swim bladder

A

rete (artery –> rete –> gas gland –> rete –> out to liver)

gas gland

106
Q

counter current in gas gland

A

rete blood in –> gas gland

gas gland blood out –> rete

107
Q

challenge of gas gland

A

need to secrete O2 into swim bladder

O2 in blood bound to Hb

dissolved in plasma –> low pO2

Hb release O2

108
Q

what drives release of O2 into swim bladder

A

lower pH

increase concentration of ions in blood to reduce solubility of O2 and other gases

109
Q

gas gland cells

A

very few mitochondria undergo glycolysis

glucose produces lactose and H+ to reduce pH

pentose produced and CO2 reduces ion concentration in blood

110
Q

arterial (afferent) gas gland

A

H+ produced by gas gland

CO2 diffusing across from efferent rete

CO2 production by gas gland (O2 release from Hb, local high pO2, O2 diffuses into swim bladder)

111
Q

blood leaving swim bladder has high…

A

pO2 –> rete –> CO2 levels –> less acidic –> Hb binds O2

112
Q

in insects

A

tracheal systems

air filled tubes

spirocles (spread or closed)

113
Q

spiracles –>

A

trachea —> tracheoles –> fluid G tips –> high O2 demand –> fluid dispersed

muscles of abdomen contract for more air movement

114
Q

diving insects O2 supply

A

take air down attached to body surface (hairs) –> air trapped in layers of hairs –> can get O2 from H2O

pO2 in air next to body 100mmHg

pO2 in surrounding water 150mmHg