What are sensory neurons located outside the CNS that respond to chemical stimuli called?

The correct choice is indeed peripheral chemoreceptors. These specialized sensory neurons are located outside the central nervous system (CNS) and are primarily responsible for detecting chemical changes in the environment, specifically changes in levels of oxygen and carbon dioxide in the blood. They play a critical role in regulating respiratory rhythms and maintaining homeostasis in response to fluctuating chemical concentrations.

Peripheral chemoreceptors are typically found in areas such as the carotid bodies and aortic bodies, where they can monitor the chemical composition of blood as it circulates through these regions. When they detect changes, they send signals to the brain to initiate appropriate physiological responses such as adjustments in breathing rate or depth.

The other options provided represent different types of neurons or receptors:

• Central chemoreceptors are located within the CNS and respond primarily to changes in the pH of cerebrospinal fluid, which indirectly reflects carbon dioxide levels in the blood.

• Exteroceptors, on the other hand, detect stimuli from the external environment, such as light, sound, or touch, rather than chemical stimuli specifically.

• Proprioceptors are found within muscles, tendons, and joints and provide information about body position and movement but do not specifically respond to chemical stimuli.

Thus, the identification of peripheral