Exam 3: Ch 13 Notes Flashcards
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
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
