Peripheral chemoreceptors
Encyclopedia
Peripheral chemoreceptors act principally to detect variation of the oxygen
concentration in the arterial blood
, whilst also monitoring arterial carbon dioxide
and pH
. They are located in the aortic body
and carotid body
, on the arch of the aorta and on the common carotid artery
, respectively. The carotid bodies are most sensitive to changes in partial pressure of arterial oxygen and pH. The aortic bodies are most sensitive to the content of arterial oxygen. In contrast, the central chemoreceptors
are relatively insensitive to oxygen concentration, and thus to hypoxia
.
A continual signal is sent, via cranial nerves IX
and X
, from the peripheral chemoreceptors to the brainstem. With a decrease in arterial oxygen tension and content or drop in plasma pH, the signal intensifies, and results in an increase in ventilation rate.
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...
concentration in the arterial blood
Arterial blood
Arterial blood is the oxygenated blood in the circulatory system found in the lungs, the left chambers of the heart, and in the arteries. It is bright red in color, while venous blood is dark red in color...
, whilst also monitoring arterial carbon dioxide
Carbon dioxide
Carbon dioxide is a naturally occurring chemical compound composed of two oxygen atoms covalently bonded to a single carbon atom...
and 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...
. They are located in the aortic body
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:...
and carotid body
Carotid body
The carotid body is a small cluster of chemoreceptors and supporting cells located near the fork of the carotid artery ....
, on the arch of the aorta and on the common carotid artery
Common carotid artery
In human anatomy, the common carotid artery is an artery that supplies the head and neck with oxygenated blood; it divides in the neck to form the external and internal carotid arteries. - Structure :...
, respectively. The carotid bodies are most sensitive to changes in partial pressure of arterial oxygen and pH. The aortic bodies are most sensitive to the content of arterial oxygen. In contrast, the central chemoreceptors
Central chemoreceptors
Central chemoreceptors of the central nervous system, located on the ventrolateral medullary surface, are sensitive to the pH of their environment....
are relatively insensitive to oxygen concentration, and thus to hypoxia
Hypoxia (medical)
Hypoxia, or hypoxiation, is a pathological condition in which the body as a whole or a region of the body is deprived of adequate oxygen supply. Variations in arterial oxygen concentrations can be part of the normal physiology, for example, during strenuous physical exercise...
.
A continual signal is sent, via cranial nerves IX
Glossopharyngeal nerve
The glossopharyngeal nerve is the ninth of twelve pairs of cranial nerves . It exits the brainstem out from the sides of the upper medulla, just rostral to the vagus nerve...
and X
Vagus nerve
The vagus nerve , also called pneumogastric nerve or cranial nerve X, is the tenth of twelve paired cranial nerves...
, from the peripheral chemoreceptors to the brainstem. With a decrease in arterial oxygen tension and content or drop in plasma pH, the signal intensifies, and results in an increase in ventilation rate.