Question

For each of the questions below, explain the physiological mechanisms that lead to changes in breathing following a bout of hyperventilation.

i) What happens to arterial PCO₂ in the time after the hyperventilation? Why does it change?

ii) List the names and the locations of the receptors that detect this change in PCO₂?

iii) Name the brain centre that interprets the information sent from these receptors and identify its location in the CNS. (1 mark)

Answer 1

1)pco2 falls in hyperventilation.On hyperventilation we push out all the co2 and thus the arterial pco2 levels fall.Normal arterial pc2 is 40.this further decreases.

2)There are basically 3 types of regulation of respiration

a)neural regulation-medulla,pons ,higher centres

In medulla-DRG(dorsla respiratory group)

VRG(ventral respiratory group)

pons-pneunotaxic centre and apnuestic centre

also there is chemical control of repsiration by receptors in a)carotid bodies and aortic bodies

b)on surface of medulla -most potent direct stimulus for central chrmoreceptor is co2