karotisbody

Karotisbody, also known as the carotid body, is a small, highly vascularized cluster of chemoreceptive cells located near the bifurcation of the common carotid artery in the neck of humans and many other mammals. It acts as a peripheral chemoreceptor that detects changes in arterial oxygen, carbon dioxide, and pH and helps regulate breathing by relaying information to the brainstem.

Structurally, the karotisbody consists mainly of type I glomus cells, the primary chemosensors, supported by type II sustentacular cells. It is enveloped by an extensive capillary network that facilitates rapid signaling. Upon stimulation, these cells release neurotransmitters that activate afferent nerve fibers, conveying chemical status to the respiratory centers.

Innervation is primarily via the carotid sinus nerve, a branch of the glossopharyngeal nerve (CN IX), which carries signals to the medullary respiratory centers. The activity of the karotisbody increases during hypoxia or hypercapnia, triggering an increase in respiratory rate and depth and influencing cardiovascular reflexes.

Developmentally, karotisbody tissue originates from neural crest cells and matures after birth in mammals. Clinically, it is notable for carotid body tumors (paragangliomas), which arise from glomus cells and may present as a slow-growing neck lump. Diagnosis relies on imaging such as MRI or CT and functional assessment, while treatment typically involves surgical resection, with radiotherapy as an option in selected cases.

Research areas include the role of karotisbody in altitude adaptation, sleep-related breathing disorders, and cardiovascular diseases, as well as potential targets for therapies aimed at modulating chemoreceptor activity.