The cessation of inspiration triggered by vagal lung inflation signals is known as the______________?
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Answer: C. Herring – Breur reflex
Explanation
The reflex prevents over-inflation of the lung tissues during deep inspiration. Vagal afferent fibers transmit signals from pulmonary stretch receptors to the medullary respiratory center. Activation of these specific pathways prematurely halts the inspiratory phase of the breathing cycle. Pulmonary stretch receptors are mechanoreceptors located within the smooth muscle of airways. These receptors discharge action potentials in direct proportion to the degree of lung inflation. The afferent signals travel exclusively along the vagus nerve directly into the brainstem.
This protective neural feedback loop prevents physical damage to delicate alveolar structures. It plays a fundamental role in regulating the normal depth and rhythm of breathing. The mechanism becomes especially prominent during strenuous exercise or high-volume ventilation. Autonomic reflex is a broad category encompassing various involuntary regulatory nervous system responses. The Bainbridge reflex specifically increases heart rate in response to elevated right atrial pressure. Dynamic stretch reflex relates to skeletal muscle proprioception rather than pulmonary mechanics.
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