Lecture 24: Blood Gas Transport Flashcards
What is the initial pressure difference that causes oxygen to diffuse into the pulmonary capillary
104-40= 64 mm Hg
What factors determine tissue PO2?
rate of oxygen transport to the tissues
rate of oxygen consumption by the tissues
What is normal intracellular PO2?
mean of 23 mm Hg
What is normal intracellular PCO2?
46 mm Hg
in order to release 5 ml of oxygen/dl of blood, what must happen?
PO2 must fall to about 40 mm Hg
Tissue PO2 cannot rise above this levle
When PO2 is high (pulmonary capillaries), oxygen _____ hemoglobin
binds
When PO2 is low (tissue capillaries), oxygen is _______ hemoglobin
released from
What happens when you increase in blood and H+ ions?
shifts oxygen hemoglobin curve to right
enhances release of oxygen from the blood in tissues
enhances oxygenation of blood in lungs
What happens when there is a decrease in blood and H+ ions?
shifts oxygen hemoglobin curve to left
occurs in lungs
How is carbon dioxide transported?
small amount dissolved in blood
about 70% is transported as carbonic acid
remainder is transported as carbamino hemoglobin
What is the Bohr effect?
• Increase in blood carbon dioxide causes oxygen to be displaced from
hemoglobin.
• Shifts oxygen-hemoglobin dissociation curve to right
What is the Haldane effect?
• Binding of oxygen with hemoglobin displaces carbon dioxide from blood:
• Binding of oxygen causes hemoglobin to become a stronger acid.
• More acidic hemoglobin has less of a tendency to bind with carbon
dioxide.
• Increased acidity of hemoglobin causes it to release hydrogen ions.
Carbon monoxide displaces oxygen on the ______ molecule
hemoglobin
How much stronger does carbon monoxide bind than oxygen?
250x
In carbon monoxide poisoning, oxygen content of blood is reduced, but PO2 may be normal, thus the blood may be ______
bright red
