Pulmonary stretch receptors

Pulmonary Stretch Receptors

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Illustration of Pulmonary Stretch Receptors

The Pulmonary Stretch Receptors are sensory nerve endings located primarily in the smooth muscle of the airways and in the lung tissue. These receptors play a crucial role in the regulation of respiratory physiology.

Function

Pulmonary stretch receptors respond to the stretch or distension of the lung tissue caused by the filling of the lungs. They send signals to the medulla oblongata in the brain, which in turn regulates the rate of breathing to prevent over-inflation of the lungs. This is known as the Hering-Breuer reflex.

Types

There are two types of pulmonary stretch receptors: slowly adapting receptors (SARs) and rapidly adapting receptors (RARs). SARs respond to sustained lung inflation, while RARs respond to changes in lung volume.

Slowly Adapting Receptors

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Illustration of Slowly Adapting Receptors

Slowly Adapting Receptors (SARs) are located in the airway smooth muscle and are activated by lung inflation. They play a key role in the regulation of breathing patterns and lung volume.

Rapidly Adapting Receptors

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Illustration of Rapidly Adapting Receptors

Rapidly Adapting Receptors (RARs) are located in the lung parenchyma and respond to both the rate and magnitude of lung inflation. They are involved in the initiation of protective reflexes such as coughing and sneezing.

Clinical Significance

Pulmonary stretch receptors have significant clinical implications. They are involved in the pathophysiology of various respiratory conditions such as asthma, COPD, and pulmonary fibrosis. Understanding the function of these receptors can help in the development of therapeutic strategies for these conditions.