Paraganglion

Overview

A paraganglion is a collection of chromaffin cells that are derived from the neural crest and are associated with the autonomic nervous system. These structures are part of the paraganglionic system, which includes the adrenal medulla and extra-adrenal paraganglia. Paraganglia are primarily involved in the production and secretion of catecholamines, such as epinephrine and norepinephrine.

Anatomy

Paraganglia are distributed throughout the body and are closely associated with the sympathetic nervous system. They are found in various locations, including the head and neck, thorax, abdomen, and pelvis.

Head and Neck

In the head and neck region, paraganglia are often referred to as glomus bodies. Notable examples include the carotid body and the jugulotympanic paraganglia. These structures play a role in chemoreception and are involved in the regulation of respiratory rate in response to changes in blood oxygen and carbon dioxide levels.

Thorax

In the thorax, paraganglia are associated with the aortic body and other structures near the heart and great vessels. These paraganglia also have chemoreceptive functions.

Abdomen

Paraganglion of the gallbladder

In the abdomen, paraganglia are found near the adrenal glands and along the sympathetic chain. The organ of Zuckerkandl is a notable abdominal paraganglion located near the aorta.

Pelvis

In the pelvis, paraganglia are associated with the urinary bladder and other pelvic organs. These structures are involved in the regulation of blood flow and smooth muscle activity.

Function

Paraganglia are primarily involved in the production of catecholamines, which are important for the "fight-or-flight response". These hormones increase heart rate, blood pressure, and blood glucose levels, preparing the body for rapid action.

Clinical Significance

Paraganglia can give rise to paragangliomas, which are rare tumors that may secrete excessive amounts of catecholamines, leading to symptoms such as hypertension, palpitations, and headaches. Paragangliomas can occur in any location where paraganglia are found, but they are most commonly seen in the head and neck region.

Related Pages

• Adrenal gland
• Sympathetic nervous system
• Chromaffin cell
• Catecholamine
• Paraganglioma