Question

Mark lives at sea level and has just arrived at high altitude. What will happen to his breathing rate in this changed environment? Why does this occur?

Select one:

a. His breathing rate will increase to offset the effects of a reduced oxygen-to-carbon-dioxide ratio in the atmosphere.

b. His breathing rate will decreases due to a decrease in blood pressure and stroke volume.

c. His breathing rate will decrease in an attempt to conserve oxygen.

d. His breathing rate will increase to offset the effects of a reduced partial pressure of oxygen in the atmosphere.

Answer 1

Answer should be D) His breathing rate will increase to offset the effects of a reduced partial pressure of oxygen in the atmosphere.

At sea level, oxygen availability is more to the tissues so partial pressure of oxygen is more, with altitude availability of oxygen decreases so the partial pressure of oxygen and it becomes almost half.

At high altitude, oxygens levels are low due to which partial pressure of oxygen also decreases as less oxygen is available to the tissues.

To overcome this effect, both heart rate and breathing rate increases.

Increase in heart rate efficiently pump the blood to meet the oxygen demand and increase in breathing rate increases availability of oxygen at respiratory membrane.