Question

In terms of V/Q mismatch, what is a physiological shunt?

a. Ventilation is impaired, but perfusion is normal

b. Ventilation is normal, but perfusion is impaired

c. Inadequate blood flow to well-ventilated areas

d. Inadequate air exchange in well-perfused areas

Answer 1

A physiological shunt in terms of V/Q mismatch occurs when there is inadequate air exchange in areas of the lung that are receiving normal blood flow, often due to functional lung impairments such as infection or edema.

Step-by-step explanation:

In terms of V/Q mismatch, a physiological shunt is defined as a scenario where there is inadequate air exchange in well-perfused areas. This typically arises due to functional impairments such as infection or edema within the lungs, leading to obstructed regions where blood flow (perfusion) remains normal, but air movement (ventilation) is compromised. Hence, the correct answer to the student's question is d. Inadequate air exchange in well-perfused areas. Physiological shunts change the ventilation/perfusion (V/Q) ratio and negatively affect gas exchange, resulting in decreased oxygen levels and increased carbon dioxide in the blood.