chemoreceptor


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chemoreceptor

 [ke″mo-re-sep´ter]
any of the special cells or organs adapted for excitation by chemical substances and located outside the central nervous system. The carotid and aortic bodies are chemoreceptors in the large arteries of the thorax and the neck; they are responsive to changes in the oxygen, carbon dioxide, and hydrogen ion concentrations in the blood. When oxygen concentration falls below normal in the arterial blood, they send impulses to stimulate the respiratory center so that there will be an increase in alveolar ventilation and thus an increase in the intake of oxygen by the lungs. Other chemoreceptors are the taste buds, which are sensitive to chemicals in the mouth, and the olfactory cells of the nose, which detect certain chemicals in the air.

che·mo·re·cep·tor

(kē'mō-rē-sep'tŏr),
Any cell that when activated by a change in its chemical milieu produces a nerve impulse. Such cells can be either 1) "transducer" cells innervated by sensory nerve fibers (for example, the gustatory receptor cells of the taste buds or cells in the carotid body sensitive to changes in the oxygen and carbon dioxide content of the blood), or 2) nerve cells proper, such as the olfactory receptor cells of the olfactory mucosa, and certain cells in the brainstem that are sensitive to changes in the composition of the blood or cerebrospinal fluid.
Synonym(s): chemoceptor

chemoreceptor

/che·mo·re·cep·tor/ (-re-sep´ter) a receptor sensitive to stimulation by chemical substances.

chemoreceptor

(kē′mō-rĭ-sĕp′tər, kĕm′ō-)
n.
A sensory nerve cell or sense organ, as of smell or taste, that responds to chemical stimuli.

chemoreceptor

[-risep′tər]
Etymology: Gk, chemeia + L, recipere, to receive
a sensory nerve cell activated by chemical stimuli. For example, chemoreceptors in the carotid artery are sensitive to the partial pressure of carbon dioxide in the blood; they signal the respiratory center in the brain to increase or decrease the rate of breathing.

che·mo·re·cep·tor

, chemoceptor (kē'mō-rĕ-sep'tŏr, kēmō-septŏr)
Any cell that responds to a change in its chemical milieu with a nerve impulse. Such cells can be either "transducer" cells innervated by sensory nerve fibers (e.g., the gustatory cells of the taste buds) or nerve cells proper, such as the olfactory receptor cells of the olfactory mucosa.

chemoreceptor

a RECEPTOR that is stimulated by contact with molecules and is capable of reacting to and differentiating between different chemical stimuli. Chemoreceptors are found where external stimuli are being sampled, for example in the taste buds and in the mucous membranes of the nose. They are also found within the body, sampling the internal environment.

che·mo·re·cep·tor

, chemoceptor (kē'mō-rĕ-sep'tŏr, kēmō-septŏr)
Any cell that responds to a change in its chemical milieu with a nerve impulse.

chemoreceptor (kē´mōrēsep´tər),

n a specialized sensory end organ adapted for excitation by chemical substances (e.g., olfactory and gustatory receptors) or specialized sense organs of the carotid body that are sensitive to chemical changes in the bloodstream.

chemoreceptor

any of the special cells or organs adapted for excitation by chemical substances and located outside the central nervous system. There are chemoreceptors in the large arteries of the thorax and the neck; called carotid and aortic bodies. These receptors are responsive to changes in the oxygen, carbon dioxide and hydrogen ion concentration in the blood. When oxygen concentration falls below normal in the arterial blood, the chemoreceptors send impulses to stimulate the respiratory center so that there will be an increase in alveolar ventilation, and consequently, an increase in the intake of oxygen by the lungs.
Other chemoreceptors are the taste buds, which are sensitive to chemicals in the mouth, and the olfactory cells of the nose, which detect certain chemicals in the air.

chemoreceptor trigger zone (CTZ)
located in the floor of the fourth ventricle; sensitive to motion, uremia, apomorphine. Activation stimulates neurons of the emetic center.
chemoreceptor tumors
References in periodicals archive ?
campaniform sensilla, spines and hairs16 have been previously reported which were contact chemoreceptors and having mechanoreceptive neuron in addition to chemoreceptive function.
And they have been shown to function as olfactory chemoreceptors in several species of Coleoptera, such as Hylobius abietis L.
Environmental effects on numbers of peripheral chemoreceptors on the antennae of a grasshopper.
Histology revealed chemodectomas characterized by extensive sheets of neoplastic chemoreceptor cells that were divided into various lobules by connective tissue; these were further subdivided into smaller nest-like structures by thin strands of fibrous septae.
The cardiovascular response to hypoxia is to increase cardiac output; heart rate increases due to the reflex responses of carotid and aortic chemoreceptors as well (1).
These drugs have multiple mechanisms of benefit, including acting on the midbrain to reduce the sensation of shortness of breath, decreasing oxygen consumption by reducing muscle activity, suppressing cough, reducing chemoreceptor sensitivity to carbon dioxide, and decreasing cardiac preload and sympathetic tone.
Peripherally acting analgesics act by blocking the generation of impulses at chemoreceptor site of pain, while centrally acting analgesics not only raise the threshold for pain, but also alter the physiological response to pain and suppress anxiety and apprehension.
The central projection of chemoreceptor axons in the crayfish revealed by axoplasmic transport.
Peripheral chemoreceptor contributions to sympathetic and cardiovascular responses during hypercapnia.
In the 1950s, regions of the brain most involved in emesis--the vomiting centre and chemoreceptor trigger zone--and a key neurotransmitter, dopamine, were isolated.
Hypoxia through a chemoreceptor mechanism increases the depth of alveolar ventilation, which can be increased by as much as 60 percent at higher elevations.