Exam 3: Ch 13 Notes Flashcards Preview

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

gas exchange challenges

SA:Vol ratio

need O2 for cellular respiration

need to dump O2 from cellular respiration

2

does an amoeba need gills?

no, it has a high surface area to volume ratio

3

atmosphere makeup

78% N2

21% O2

9% other

0.3% CO2

4

gas exchange must meet ______ specific demands

tissue specific demands

5

problem... where do you live?

sea level

altitude

in water

6

in the water, O2 is only available...

1/30th of atmosphere

dissolves from atmosphere

produced from photosynthesis

7

water in diff salinities/temps

fresh

salt @ 30 degrees 4.34 ml O2/L

salt @ 15 degrees 5.75 ml O2/L

8

water has layers

salinity and temp restrict O2 movement

less diffusion

9

how to max diffusion

large surface area

minimize distance to diffuse

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

10

hemoglobin increases

carrying capacity of blood

11

how do we increase carrying capacity more

RBC increase production of EPO

plasma

doping: 1 pt of blood --> spin --> give RBC back "treacle" viscous blood

12

ice fish don't have a _______ pigment

respiratory

low temp --> more O2 dissolved

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

increased blood volume and cardiac output

13

hemoglobin structure

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

14

Hb + O2 vs. Hb by itself

oxyhemoglobin; deoxyhemoglobin

15

Hb is better at binding..

carbon monoxide 200x

displaces O2

no detection system

16

sickle cell anemia

Hb clumps, distorts RBC

lower O2 carrying capacity

RBC get stuck in capillaries

resistance to malaria

17

myoglobin

muscles 1 subunit

no subunit cooperativity

not as well tunes

18

Hb + O2 cooperative binding

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

how is Hb tuned

more release at partial pressures that are experienced in metabolic tissues

20

Bohr effect

more acidic conditions = less O2 bound to Hb

ex. 30mmHg pH 7.4 = 30% saturation

pH 7.2 = 15% saturation

21

what conditions wound you find in exercising muscle

more acidic

less O2, more CO2

higher temp

all cause Hb to release more O2

22

Hb has a changing affinity for O2 depending on

conditions of surrounding tissue

23

developmental changes of Hb

different Hbs

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

24

CO2 transport

oxygenated blood has less CO2 carrying capacity

deoxygenated blood has more CO2 carrying capacity

25

CO2 transport in peruvian, tibetan, and kenyan people

lower CO2 binding Hb

increased RBC, Hb, NO

more heart capacity

26

andean populations

increased RBC + Hb

many unsaturated RBC

viscous blood

27

himalayan population consists of which two groups

tibet and nepal

28

himalayan populations CO2 transport

O2 sat lower than sea level

high levels of NO (240x)

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

29

himalayan populations breathe...

deeper and faster

EPAS1 - monitors O2 levels

prevent overproduction of RBC

30

kenyan populations

increased rate of O2 transfer from alveoli to blood

Hb levels and O2 saturation same as sea level

31

major things that Hb binds

O2

H+

CO2

32

both __ and __ compete w/ O2 for Hb binding

H+, CO2

33

CO2 to HCO3- and H2CO3 ratios

CO2:H2CO2 1000:1

CO2:HCO3- 1:20

34

most CO2 in blood is transported by...

HCO3-

35

carbamino Hb

protein-NH2 + CO2

36

can deoxygenated blood carry more CO2 than oxygenated blood?

yes

37

CO2 pathway in blood

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

38

does muscle produce CO2?

yes

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

39

CO2 in lungs

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

40

carbonic anhydrase design tweak

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

41

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

right, more

42

reasons for O2 delivery

reduced pO2

H+ competed for Hb binding

CO2 competes to form carbamino Hb

43

is there gas transfer in cartilage?

no

44

cystic fibrosis

mutated Cl- transporter, thick mucus not removed

45

terminal bronchioles are made of

smooth muscle

46

asthma

inflammation

smooth muscle contraction

47

growth of alveoli

birth to 8 yrs old increase # of alveoli

8 to adult increase size of alveoli

environment dependent

48

at rest human tidal volume is...

10% of max

49

why do amphiuma breath 1/hr

vulnerable at surface

tidal volume 50% of max

during 1hr, pO2 volume changes

pCO2 stable --> lost through skin

50

blood supply to lung

apex lower

base higher

51

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

vasoconstriction to that region shifts more blood to better functioning regions

"hypoxic" pulmonary vasoconstriction involves ion channels

52

amphiuma live in ____ O2 water

low

heart rate is steady

intake is 50% max lung capacity

O2 levels fluctuate between breaths

CO2 levels remain constant --> released across skin

53

lung capillaries

sheet w/ film of blood between 2 surfaces

if you are vertical, less pressure so thinner sheet

54

is pulmonary BP lower than systemic?

yes

55

what channels are in capillary membranes

K+

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

56

at altitude you get chronic ______

hypoxia

low O2 region in lung --> vasoconstriction

low O2 in muscles --> vasodilation

57

frog pulmonary cutaneous system

gas exchange to lungs/skin

non-rhythmic breathing

breathing increases blood flow to skin

systemic blood flow is constant

58

human diaphragm and ribcage

diaphragm down and ribcage elevated

lowers pressure in lungs so air can come in

breathe in and out incomplete gas exchange: residual air

59

bird breathing

air sacs change volume

lungs --> gas exchange

"flow through" system - 2 cycles of air to pass through

60

alveolar (bag) surface

moistness causes surface tension

lipoprotein surfactants reduce surface tension for more efficient breathing

61

premature babies don't produce ________

surfactant

causes positive pressure

add surfactants

inject mom w/ cortisol (type II cells mature)

62

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

air

slower diffusion (10,000x)

gills --> unidirectional flow, need higher flow rate

63

gill breathing

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

lower flow of mouth

expiration --> mouth closed, mouth flow raised

64

counter current system

more efficient exchange across whole length of gill surface

diffusion gradient maintained

H2O in one direction, blood in opposite direction

65

counter current system works if...

fast H2O flow

less loss of O2

gradient maintained

66

ram ventilation

fish that constantly swim w/ mouths open

67

Va / Q ~ 1 humans

Va / Q ~ 10 fish

Va = rate of ventilation

Q = rate of diffusion

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

68

respiratory center receptors

chemoreceptors

mechanoreceptors (lung-stretch)

69

chemoreceptors

sense CO2, pH, O2

aortic bodies: CO2

carotid bodies: pH

70

lung-stretch receptors

inflate lungs sensed --> inhibit inspiration center via vagus nerve

71

central pattern generator

depth and amplitude

72

rhythm generator

frequency

73

inspiration center neurons

phrenic nerve

respiratory motor neurons

lower pressure in lungs

air intake

74

increased alveolar pCO2 leads to...

increased phrenic nerve activity --> increased inspiration

75

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

CO2 levels

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

76

carotid body

better detector of pH and CO2 than O2

77

aortic body

better detector of O2 than CO2 or pH

78

medulla

pH, CO2 in CSF

79

carotid body is activated by

high CO2

low pH, O2

increases firing rate --> respiratory center --> increased breathing

80

structure of carotid body

vessel network and glomus cell detector release nt

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

decreased pO2 --> increased breathing rate

81

medulla mechanism

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

82

why CSF medulla?

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

effect of higher breathing rate

more release of CO2

pH returns to normal

84

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

O2 levels

CO2 more soluble in H2O so O2 is limiting factor

85

at altitude, pulmonary edema

fluid in lungs makes shortness of breath crackling sounds

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

86

O2 levels vary in H2O

salt vs fresh

warm vs. cold

photosynthesis

O2 using organisms

mixing from surface

87

fish adapted to cope w/ wide range of pO2

stop feeding

lower metabolism

less swimming

more gill ventilation

move to cooler H2O

less breeding

88

humans @ altitude

low pO2 carotid/aortic receptors

higher ventilation and CO2 elimination

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

89

short-term human adaptation

reset trigger levels

90

long-term hypoxia

gradual increase in ventilation

systemic vasodilation

higher cardiac output

up to 33% increase in blood volume

91

low blood CO2 levels lead to

high pH

increase Hb affinity for O2

92

good/bad of increased Hb affinity for O2

good: increased O2 uptake in lungs

bad: less O2 deposition in tissues

93

body's response to increased Hb affinity for O2

more DPG production

binds to deoxyhemoglobin to reduce affinity for O2

more O2 released

94

hypoxia leads to _____ production

HIF-1 (erythropoetin) RBC production

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

95

diving animals have __ storage

O2

96

diving animals have __ storage

O2 in lungs, blood, myoglobin

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

97

during a dive...

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

98

exhalation at the beginning of a dive...

reduces buoyancy

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

99

humans at birth

aquatic to air breathing (hypoxia)

early postnatal tissue is hypoxia resistant

100

10m = _atm

1atm

surface 1atm 1L --> 10m, 2atm 500ml

101

buoyancy control

swim bladder

made of mostly O2, relatively gas impermeable structure

high pO2

H2O/blood have low pO2

102

swim bladder challenge

O2 in against conc gradient

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

103

mechanism of diffusion into swim bladder

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

104

cells in swim bladder

patch of foregut cells that are gas impermeable

slow leak

105

specialized structures of swim bladder

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

gas gland

106

counter current in gas gland

rete blood in --> gas gland

gas gland blood out --> rete

107

challenge of gas gland

need to secrete O2 into swim bladder

O2 in blood bound to Hb

dissolved in plasma --> low pO2

Hb release O2

108

what drives release of O2 into swim bladder

lower pH

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

109

gas gland cells

very few mitochondria undergo glycolysis

glucose produces lactose and H+ to reduce pH

pentose produced and CO2 reduces ion concentration in blood

110

arterial (afferent) gas gland

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

blood leaving swim bladder has high...

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

112

in insects

tracheal systems

air filled tubes

spirocles (spread or closed)

113

spiracles -->

trachea ---> tracheoles --> fluid G tips --> high O2 demand --> fluid dispersed

muscles of abdomen contract for more air movement

114

diving insects O2 supply

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