transport of oxygen and co2 Flashcards
CO2 production by cells
200ml/min
metabolic arteriovenous CO2 difference
40ml/L
metabolic arteriovenous O2 difference
50ml/L
O2 use by cells
250ml/mi
tissue pCO2
> 50
tissue PO2
> 10
hypoxic hypoxia
inadequate O2 uptake in lungs
stagnant (ischemic) hypoxia
inadequate blood flow to an organ (arteriosclerosis, PVD, stroke, MI)
anemic hypoxia
inadequate blood o2 carrying capacity. inactivated hemoglobin
histotoxic hypoxia
interference with mitochondrial respiration (like cyanide poisoning)
normal Hb
15g/dL
RBC carry ___ times more o2 than plasma
65
how many subunits does hb have
4
each gm of Hb can carry up to how much o2?
1.31ml
what shape is the Hbo2 curve
sigmoid
the ratio of o2 bound to hb compared to total amount that can be bound is
oxygen saturation
maximal amt of o2 bound to hb is
oxygen capacity
***what is the Hb P50 point
27!!!
what is your paO2 when the sat is 90
60
what is your paO2 when the sat is 50
27!
rough rule for sat to Pao2
40,50,60 for sat 70,80,90
the higher the affinity, the ___ the saturation
higher
the top of the curve represents
lungs
the middle of the curve represents
capillaries
the starting point of the curve represents
tissues
the x axis on curve
po2
the y axis
hb sat %
carbon monoxide has ___ times the affinity for Hb than O2
250
nitric oxide binds to Hb _____ times more strongly than o2
200000.
what is NO used for
to treat pulmonary hypertension
as PaO2 in the tissues decreases, the __ affinity Hb has for it, so…
less, so O2 is dumped in the tissues
left =
love = lungs
right =
release
which way does alkalosis shift the curve
left
which way does acidosis shift the curve
right
which way does hyperthermia shift the curve
right
which way does hypothermia shift the curve
left
which way does increased 2,3, DIPG shift the curve
right
which way does carboxyhemoglobin and methemoglobin shift the curve?
left
which way does increased H+ shift the curve
right
which way does increased pCO2 shift the curve
right
Bohr effect
Hb releases more o2 in an acidic environment. an increase in H+ decreases the Hb’s affinityy for o2. its the cells way of asking hb to release o2 to support aerobic metabolism
PRBC’s in the package shift the curve
left… because cold and less 2,3. dipg
myoglobin has ___ affinity for O2, and this causes a shift to the ____
increased, left
fetal blood causes a shift
left
O2 content in blood is the sum of
carried on Hb and dissolved
shift up is caused by
increased 02 capacity-
shift down is caused by
decreased 02 capacity - anemia
CO production in a resting adult
200ml/min. increases 6 fold with exercise.
what are the 3 ways CO2 is transported by blood
as a gas dissolved directly in food, bicarb, ad bound to hb and plasma
what is the MAIN way co2 is transported
HCO3 bicarb! 70%
venous blood transports ___ CO2 than arterial blood
more
haldane effect
upon binding o2, HB releases CO2 and H+ which in turn is converted to CO2. increased O2 causes the erythrocyte to release CO2. deoxygenated blood (venous) is able to carry more CO2
shifting the curve ___ causes decreased o2 delivery to tissues
left
the reaction that converts CO2 to HCO3 requires
the enzyme carbonic anhydrase
mixed venous blood in pulm artery sat and pa02
75% paO2 40
what binds irreversibly to hb
nitric oxide
venous hb affinity shift
Po2 of 70 mmHg Shift to the right reducing the affinity for O2 below. shifting occurs bc of Bohr effect - an increase in H+ decreases hb’s affinity for o2. increases delivery of o2 to tissues
Cao2 formula
(SO2 x hb x 1.31) + (Po2 x 0.003)
DO2 (oxygen delivery)
caO2 x CO
ability to bind with CO2 is ___ in deoxygenated hb
increased
the presence of HB in normal arterial blood increase its oxygen concentration approx how many times?
70
an increase in what increase 02 affinity of hb
carbon monoxide
severe anemia with normal lugs, you’d expect
low oxygen concentration of mixed venous blood
in carbon monoxide poisionig you’d expect
reduced oxygen concentration of mixed venous blood
