Which of the following shows a correct sequence of events in pulmonary embolism?
A) Hypoxic vasoconstriction occurs, causing an increase in surfactant production.
B) Dead space develops, causing dislodgement of a portion of the thrombus.
C) Hypoxemia inhibits the production of surfactant, causing alveolar collapse.
D) Alveoli collapse, causing an increase in the ventilation-perfusion ratio.

Question

Quizplus · Accepted Answer

In pulmonary embolism, a thrombus (blood clot) lodges in a pulmonary artery, blocking blood flow to the lung tissue supplied by that artery. This results in a decrease in oxygen supply to the lung tissue, causing hypoxemia (low oxygen levels in the blood). Hypoxemia inhibits the production of surfactant, which is a substance that helps to keep the alveoli (tiny air sacs in the lungs) inflated. The loss of surfactant can cause alveolar collapse (atelectasis), leading to a decrease in lung compliance and an increase in the ventilation-perfusion ratio. Hypoxic vasoconstriction may occur as a response to the reduced oxygen supply, but it does not cause an increase in surfactant production. Dead space may develop if blood flow is diverted to other areas of the lung, but it does not cause dislodgement of the thrombus.

Which of the Following Shows a Correct Sequence of Events