chemoreceptors Nerve endings stimulated to produce nerve impulses by contact with chemical substances or as a result of changes in the local concentration of chemical substances. The receptors for smell and taste, those for oxygen in the carotid bodies and those for glucose in the pancreas are of this type.
chemoreceptors neural receptors that respond to some local chemical change. Usually refers to those which influence the respiratory and cardiovascular control centres in the brain stem: the medullary chemoreceptors, sensitive to pH changes in the cerebral extracellular fluid, and the arterial chemoreceptors which continually sense and respond to changes mainly in blood oxygen, carbon dioxide and pH, leading to appropriate reflex adjustments via afferent nerves to the brain stem control centres (e.g. increase in ventilation if arterial oxygen tension tends to fall and/or carbon dioxide to rise). See also breathing, hypoxia.
chemoreceptors cells, or groups of cell membrane molecules, which initiate nerve action potentials