Kemoreceptiva

Kemoreceptiva refers to the sensory mechanisms that detect chemical stimuli and convert them into neural signals. Chemosensation is fundamental for evaluating nutrients and toxins, guiding feeding and social behavior, and maintaining internal balance by monitoring the chemical composition of the body’s surroundings. The term encompasses several systems and cell types across organisms, from animals to microbes and plants, that respond to chemical cues in the environment or within the body.

In animals, the best-known chemoreceptive systems are gustation (taste) and olfaction (smell). Taste receptor cells reside in taste buds and detect basic modalities such as sweet, sour, salty, bitter, and umami; different receptor families and ion channels mediate these tastes. Olfactory receptor neurons express a large repertoire of odorant receptors (mostly G protein–coupled receptors) that recognize volatile chemicals, enabling the perception of a wide range of odors. Peripheral chemoreceptors, such as carotid and aortic bodies, sense arterial oxygen, carbon dioxide, and pH, contributing to respiratory and cardiovascular regulation. Central chemoreceptors in the brainstem respond to pH changes in the cerebrospinal fluid, influencing ventilation.

Outside animals, chemoreception also appears in bacteria, where chemoreceptors mediate chemotaxis toward attractants or away from repellents via specialized signaling pathways, and in plants, where chemical sensing modulates growth, defense, and development.

Clinical relevance varies with the system: olfactory and gustatory disorders affect quality of life, while dysfunction of central or peripheral chemoreceptors can impact breathing, blood gas regulation, and homeostasis.