Extra-adrenal paraganglia

Extra-adrenal paraganglia

Paraganglia are neuroendocrine cells associated with the autonomic nervous system. They can be adrenal (medulla) or extra-adrenal. Extra-adrenal paraganglia occur throughout the sympathetic nervous system and along some branches of the parasympathetic glossopharyngeal and vagus nerves. There are four subgroups: 1 Sympathetic : the largest cluster is the organ of Zucker kandl, which is located at the aortic bifurcation or close to the origin of the inferior mesenteric artery . 2 Chemoreceptor : including aortic and carotid bodies that assist in the regulation of respiration. 3 Visceral–autonomic : in the urinary bladder and peripheral blood vessels. 4 Intravagal : situated within or adjacent to the vagal trunk. Neoplasms of extra-adrenal paraganglia are called para gangliomas (PGLs). Tumours of chemoreceptors are usually referred to as chemodectomas (see Chapter 52 ) and those from parasympathetic ganglia are termed glomus tumours.