Pulmonary stretch receptor

Sensory receptors in the lungs that respond to stretch

Pulmonary stretch receptors are mechanoreceptors found in the lungs that are sensitive to the stretching of the lung tissue. These receptors play a crucial role in the regulation of breathing and are involved in the Hering–Breuer reflex, which helps to prevent over-inflation of the lungs.

Anatomy and Physiology

Pulmonary stretch receptors are located in the smooth muscle of the airways, particularly in the trachea and bronchi. They are a type of slowly adapting stretch receptor, meaning they continue to respond to a stimulus over a prolonged period. These receptors are innervated by the vagus nerve, which transmits sensory information to the brainstem.

When the lungs inflate, the pulmonary stretch receptors are activated by the mechanical stretching of the lung tissue. This activation sends signals via the vagus nerve to the respiratory centers in the medulla oblongata and pons of the brainstem. The primary function of these signals is to modulate the depth and rate of breathing.

Function

The primary function of pulmonary stretch receptors is to prevent over-inflation of the lungs. This is achieved through the Hering–Breuer reflex, which inhibits inspiration when the lungs are inflated to a certain volume. This reflex helps to regulate the breathing cycle and maintain optimal lung function.

In addition to their role in the Hering–Breuer reflex, pulmonary stretch receptors also contribute to the sensation of lung inflation, which can influence the conscious perception of breathing effort and respiratory discomfort.

Clinical Significance

The function of pulmonary stretch receptors can be affected in various respiratory conditions. For example, in chronic obstructive pulmonary disease (COPD), the sensitivity of these receptors may be altered, contributing to the sensation of dyspnea (shortness of breath). Understanding the role of pulmonary stretch receptors can aid in the development of therapeutic strategies for managing respiratory disorders.

Related Pages

• Hering–Breuer reflex
• Vagus nerve
• Medulla oblongata
• Pons
• Chronic obstructive pulmonary disease