Glomus cell
Encyclopedia
- The glomus cell is not to be confused with the glomus bodyGlomus bodyA glomus body is a component of the dermis layer of the skin, involved in body temperature regulation. The glomus body consists of an arterio-venous shunt surrounded by a capsule of connective tissue. Glomus bodies are most numerous in the fingers and toes...
found in the dermis layer of the skin.
A glomus cell is a peripheral chemoreceptor, located in the carotid bodies
Carotid body
The carotid body is a small cluster of chemoreceptors and supporting cells located near the fork of the carotid artery ....
and aortic bodies
Aortic body
In the human heart, the aortic body is one of several small clusters of chemoreceptors, baroreceptors, and supporting cells located along the aortic arch.-Function:...
, that helps the body regulate breathing. When there is a decrease in the blood's pH
PH
In chemistry, pH is a measure of the acidity or basicity of an aqueous solution. Pure water is said to be neutral, with a pH close to 7.0 at . Solutions with a pH less than 7 are said to be acidic and solutions with a pH greater than 7 are basic or alkaline...
, a decrease in oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...
(pO2), or an increase in carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
(pCO2), the carotid bodies and the aortic bodies signal the medulla oblongata
Medulla oblongata
The medulla oblongata is the lower half of the brainstem. In discussions of neurology and similar contexts where no ambiguity will result, it is often referred to as simply the medulla...
(specifically the dorsal inspiratory center in the medulla oblongata) to increase the volume and rate of breathing. The glomus cells have a high metabolic rate and good blood perfusion and thus are sensitive to changes in arterial blood gas tension. The signalling within the chemoreceptors is thought to be mediated by the release of neurotransmitter
Neurotransmitter
Neurotransmitters are endogenous chemicals that transmit signals from a neuron to a target cell across a synapse. Neurotransmitters are packaged into synaptic vesicles clustered beneath the membrane on the presynaptic side of a synapse, and are released into the synaptic cleft, where they bind to...
s by the glomus cells, including dopamine
Dopamine
Dopamine is a catecholamine neurotransmitter present in a wide variety of animals, including both vertebrates and invertebrates. In the brain, this substituted phenethylamine functions as a neurotransmitter, activating the five known types of dopamine receptors—D1, D2, D3, D4, and D5—and their...
, noradrenaline, acetylcholine
Acetylcholine
The chemical compound acetylcholine is a neurotransmitter in both the peripheral nervous system and central nervous system in many organisms including humans...
, substance P
Substance P
In the field of neuroscience, substance P is a neuropeptide: an undecapeptide that functions as a neurotransmitter and as a neuromodulator. It belongs to the tachykinin neuropeptide family. Substance P and its closely related neuropeptide neurokinin A are produced from a polyprotein precursor...
and enkephalin
Enkephalin
An enkephalin is a pentapeptide involved in regulating nociception in the body. The enkephalins are termed endogenous ligands, or specifically endorphins, as they are internally derived and bind to the body's opioid receptors. Discovered in 1975, two forms of enkephalin were revealed, one...
s.
See also
- ParagangliomaParagangliomaA paraganglioma is a rare neuroendocrine neoplasm that may develop at various body sites . About 97% are benign and cured by surgical removal; the remaining 3% are malignant because they are able to produce distant metastases...
, a tumor of glomus cells