Physiology Spring L9 Altitude Hypoxia

Front 1

What is the barometric pressure at 18,000 feet?

Back 1

380 mmHg, so 1/2 sea level

Front 2

How does ventilation rate change at high altitude?

Back 2

RR will increase, hyperveniltation due to hypoxemia

Front 3

How does Hb concentration change at high altitude?

Back 3

this will Increase, with an increase in RBC concentration

Front 4

How does 2,3 DPG concentration change at high altitude?

Back 4

this will increase

Front 5

How does the O2-Hb dissociation curve change at high altitude?

Back 5

this will shift to the right, lowering the affinity for Oxygen at all pressures. this increase the P50 of O2

Front 6

What is the most significant response to high altitude? what O2 concentration does it respond to?

Back 6

this responds to PAO2's of 60mmHg or less upon equilibration.

this stimulates the peripheral chemoreceptors- (aortic/carotid) with its 60 mmHg or less of PaO2

increases breathing rate

Front 7

What causes Polycythemia? what are the benefits and draw backs?

Back 7

this is causes by hypoxia- increase EPO production.

this is good because it increase Hb and O2 carrying capacity

this is bad because is increases blood viscosity, increasing resistance

Front 8

How does 2,3 DPG affect the O2-Hb dissocation curve?

Back 8

this results in a RIGHT shift, so it has a lower affinity for O2, and more likely to dump oxygen

Front 9

What is the A-a gradient?

Back 9

this is the difference between Alveolar O2, and arterial O2 partial pressures

Front 10

What is the equation for A-a gradient?

Back 10

A-a= (PIo2- PAco2/R)- PaO2

Front 11

What does the A-a gradient represent?

Back 11

this represents and equilibration between the alverolar, and arterial blood

Front 12

What does Daltons law state?

Back 12

Px=Pb X F

(partial pressure of X= barometric pressure X Fraction)

Front 13

what chemoreceptors stimulate hyperventilation due to hypoxia?

Back 13

peripheral chemoreceptors