What is the Origin of Chemoreceptor Sensitivity?

The concept of chemoreception is a cornerstone of neurophysiology and respiratory control, originating from the study of reflex arcs that govern breathing rate and depth. These receptors, located in areas like the carotid and aortic bodies, represent a primary biological defense mechanism against hypoxia and hypercapnia. Endocrine status can subtly influence the set points and responsiveness of these sensors.

What is the Mechanism of Chemoreceptor Sensitivity?

Changes in blood chemistry, particularly a rise in carbon dioxide or a drop in oxygen, trigger chemoreceptors to send afferent signals to the brainstem's respiratory centers. This signal cascade immediately adjusts ventilation to restore normal blood gas levels. Hormones like progesterone can increase the ventilatory response to carbon dioxide, thereby altering the inherent sensitivity of this homeostatic feedback loop.

Chemoreceptor Sensitivity ∞ Area

Chemoreceptor Sensitivity

Meaning

The responsiveness of specialized sensory receptors, known as chemoreceptors, to changes in the chemical composition of the blood or surrounding fluid. Key examples include the sensitivity of peripheral chemoreceptors to fluctuations in arterial oxygen, carbon dioxide, and pH levels. This physiological parameter is crucial for the precise homeostatic regulation of respiration and circulation.