Transport of O2 and CO2 in blood Flashcards
In solution, only _____ gas molecules generate the partial pressure
dissolved
Methemoglobin
hemoglobin variant, iron is in Fe+++ state
does not bind O2
What are some things that can cause methemoglobin
nitrites and sulfonamides
deficiency of methemoglobin reductase
What is the O2 binding capacity
the maximum O2 volume that can combine with Hb
depends on Hb concentration and binding procperties
What is the O2 content
actual amount of O2 per volume of blood
What is the equation for O2 content
O2 binding capacity x SaO2 +dissolved O2
What is the SaO2
% of heme groups bounds to O2
How do you calculate O2 delivery
CO x oxygen content
What are some factors that affect tissue oxygen delivery
CO in 3rd degree heart failture
hemogoblin in anemia
decreased RBC production in chronic kidney failure
What is the normal shape of the O2-Hb dissociation curve?
sigmoidal
What is the flat upper part of the O2-Hb dissociation curve
ensures constant oxyhemoglobin saturation for aterial blood despite wide variations in O pressure
What is the steep lower part of the O2-Hb dissociation curve
considerable amounts of O can be unloaded to peripheral tissues with only a small drop in capillary PO2
Under normal conditions about ______ of oxygen are transported from lungs to tissues by each 100 mL of blood flow
5 mL
Hb automatically delivers O2 to tissues at _________
a tight PO2 range
What does an increase in P50 mean
weaker binding
Oxygen gets released more easily
What does a decrease in P50 mean
tighter binding
Oxygen wants to stay bound
How does fever affect Hb-O2 binding
right shift,
O2 gets released more easily
How does hypothermia affect Hb-O2 binding
left shift
O2 wants to stay bound
How does decreasing pH affect Hb-O2 binding
right sift
O2 gets released more easily (bohr effect)
How does increasing pH affect Hb-O2 binding
left shift
O2 wants to stay bound
How does 2,3 DOG affect Hb-O2 binding
right shift
O2 gets released more easily
What are the symptoms of CO poisoning
altered reaction time
blurred vision
unconsciousness
What is the main form of CO2 transport in the body
bicarb in RBCs
7% of CO2 is in what form
dissolved
