AEMCA Practice Exam

Stretch receptors in the lungs are located in which part?

1. Alveoli

2. Epithelial cells

3. Smooth muscle layer

4. Pulmonary capillaries

The correct answer is: Smooth muscle layer

Stretch receptors in the lungs are primarily located in the smooth muscle layer. These receptors play a crucial role in the regulation of breathing and respiratory function. They detect changes in the volume and stretch of the lung tissue during inhalation and exhalation, providing feedback to the central nervous system about the status of lung inflation. This feedback is essential for maintaining proper respiratory rhythm and preventing overinflation of the lungs. The other options refer to different structures: the alveoli are the sites of gas exchange, the epithelial cells line the respiratory tract but are not primarily responsible for stretch detection, and the pulmonary capillaries are involved in blood-gas exchange rather than sensing lung expansion. Thus, the correct choice highlights the specific anatomical location responsible for monitoring the lung's stretch during respiratory cycles.