Oxygen transport Flashcards
How is oxygen transported
- small amount of O2 is dissolved in plasma (2% or 0.3ml per 100ml)
- O2 binds to hemoglobin (specialized protein in erythrocytes)
-binding can be affected by pressure
how much O2 is dissolved in plasma?
0.3 ml O2 per 100 ml plasma
3 ml per 1L
15 ml per 5L
why is the dissolved O2 and CO2 in plasma important?
They set the partial pressures. PO2 and PCO2
how much O2 binds to hemoglobin?
20ml of O2 per 100ml of blood
197 ml O2 per 1 L
how much more effective is hemoglobin than plasma when it comes to O2 carrying capacity?
hemoglobin is 65-70 times better
describe the oxyhemoglobin dissociation curve
the oxyhemoglobin dissociation curve is the relationship that describes the influence of PO2 on the saturation of hemoglobin (SbO2)
What makes the oxyhemoglobin dissociation curve shift right
- higher CO2 level
- higher acidity (more H+ = less pH)
- increased DPG-2,3 (from glycolysis)
- Exercising
- Higher temperature
what is the Bohr effect?
The Bohr effect describes how the hemoglobin’s affinity for oxygen decreases as the CO2 level and H+ level increase (along with change in some other factors)
What is myoglobin
- Iron protein found only in skeletal muscle and cardiac muscle
- only one iron atom – only attach one O2
- extra source of O2 for muscle
- doesn’t follow S shape of Hb – allows Mb stay saturated at low PO2
- no Bohr effect
How does high altitude influence the oxygen saturation
As the altitude gets higher, the atmospheric pressure drops.
The body is unable to take in as much air, causing the PAO2 and PVO2 to drop
Blood saturation drops
Why do people ascend and descend many times when climbing the Everest
- to prevent HACE (High altitude Cerebral Edema)
- prevent other high altitude illnesses
- help produce more RBCs
Who are the Sherpas
people from Nepal who live in the Himalayas for centuries and trained to help the climbers
