Question

2, High altitude pulmonary edema (and high altitude cerebral edema) are the major causes of death from altitude sickness, triggered by hypoxic conditions.

a. Recall that alveolar ventilation and blood flow to pulmonary capillaries are matched to maximize diffusion of oxygen into the blood. when climbers eceed about 2500m of altitude they experience significantly low levels of atmospheric oxygen. How does this affect the state of contraction of their pulmonary arterioles?

b. How would hypoxix conditions affect pressure in the pulmonary circuit?

c. Explain why climbers suffereing from alitude sickness often suffer from coughing that yields a pink, frothy fluid.

d. Climbers spend several weeks below 15,000 ft adjusting to thec altitude before attempting to reach the summit of Mt. Everest. Fill in the following table about the hormone that is released under these hypoxic conditions. (5 pts) Hormones Source of Hormone Stimulus for Target Tissue Release Physiological Response e. There is a significantly elevated risk of stroke and heart attack associated with the response to the hormone in the table above. Explain why. (1 pt). f. Ventilation rate also increases at high altitude. What stimulates this increase in respiration rate? (1 pt) g. Draw in an arrow under the cquation below, showing which way the increase in ventilation rate above will shift the equilibrium. Will plasma pH increase or decrease? (2 pts)

Answer 1

Answer: Climbers exceed about 2500m of altitude they experience significantly low levels of atmospheric oxygen and this affect the state of contraction of their pulmonary arterioles by many ways as due to low levels of oxygen and while breathing the lungs didn't get sufficient oxygen to carry to blood and lungs. This causes contraction of pulmonary arterioles.

Hypoxia causes dilatation in systemic arteries and constriction in small pulmonary arteries. Hypoxic pulmonary vasoconstriction is an important mechanism by which pulmonary blood flow is controlled in human beings and contraction of vascular smooth muscle in the pulmonary circulation in response to a low pressure of oxygen.

Sometimes when climbers suffering from altitude sickness often suffer from coughing that yields a pink, frothy fluid because when there is low level of oxygen and lungs didn't get sufficient amount of oxygen, the blood from the artery comes to the pulmonary veins of lungs and hence little blood comes out while coughing. But it can become serious if there is a negligible amount of oxygen.