Aortic body
Template:Short description Template:Infobox anatomy
The aortic bodies are one of several small clusters of peripheral chemoreceptors located along the aortic arch. They are important in measuring partial pressures of oxygen and carbon dioxide in the blood, and blood pH.
Structure
The aortic bodies are collections of chemoreceptors present on the aortic arch.<ref name=":0">Template:Citation</ref> Most are located above the aortic arch,<ref name=":4">Template:Citation</ref> while some are located on the posterior side of the aortic arch between it and the pulmonary artery below.<ref name=":3">Template:Citation</ref> They consist of glomus cells and sustentacular cells.<ref name=":0" />
Some sources equate the "aortic bodies" and "paraaortic bodies", while other sources explicitly distinguish between the two.<ref>Template:MeshName</ref><ref>Template:MeshName</ref> When a distinction is made, the "aortic bodies" are chemoreceptors which regulate the circulatory system, while the "paraaortic bodies" are the chromaffin cells which manufacture catecholamines.<ref name="PiskuricNurse2013">Template:Cite journal</ref>
Function
The aortic bodies measure partial gas pressures and the composition of arterial blood flowing past it.<ref name=":1" /> These changes may include:
- oxygen partial pressure.<ref name=":1" /><ref name=":2">Template:Citation</ref>
- carbon dioxide partial pressure.<ref name=":1">Template:Cite journal</ref><ref name=":2" />
- pH (indirectly affected by carbon dioxide concentration).<ref name=":0" /><ref name=":2" />
They are particularly sensitive to changes in pH.<ref name=":4" /> Aortic bodies are more sensitive detectors of total arterial blood oxygen content than the carotid body chemoreceptors, which are more sensitive detectors of the partial pressure of oxygen in the arterial blood.<ref name=":2" />
The aortic bodies give feedback to the medulla oblongata, specifically to the dorsal respiratory group, via the afferent branches of the vagus nerve (cranial nerve X).<ref name=":0" /><ref name=":3" /> The medulla oblongata, in turn, regulates breathing and blood pressure.
Clinical significance
A paraganglioma, also known as a chemodectoma or carotid body paraganglioma, is a tumor involving an aortic body.<ref>Template:Cite journal</ref><ref>Template:Citation</ref>
It has been hypothesized that inflammatory responses involving the aortic body play a role in the development of intractable and severe apnea known to occur in a subset of premature infants.<ref>Template:Cite journal</ref>Template:Vague
See also
References
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Template:Cardiovascular physiology Template:Arteries of chest