Ventilation under Unusual Conditions

Question 1

Which receptors detect acute hypoxia?

Answer 1

Peripheral chemoreceptors

Question 2

What effect does increased ventilation have on the pH of cerebrospinal fluid?

Answer 2

Increased ventilation, decreases levels of CO2, so decreases the pH of CSF, making it more alkaline

Question 3

Which cells export excess HCO3- from cerebrospinal fluid?

Answer 3

Choroid plexus cells

Question 4

Why do people often get splenomegaly on descent from high altitudes?

Answer 4

. At high altitude, more RBCs are produced (polycythaemia)
. When coming back down, lots of excess RBCs need to be broken down, do the spleen becomes enlarged from all this extra work

Question 5

Why do people get nitrogen narcosis on descent into water?

Answer 5

Nitrogen more soluble deeper in water, so more nitrogen dissolved in blood

Question 6

Why do people get the bends when ascending in water?

Answer 6

Nitrogen becomes less soluble and forms bubbles as it comes out of solution

Question 7

What is another name for orthostatic hypotension?

Answer 7

Postural hypotension