An Endoneural Microglomus of the Recurrent Laryngeal Nerve

Abstract

A micro-organ composed of islands resembling carotid body cells located in the endoneural space of the rat recurrent laryngeal nerve is described. The microglomus is located 5 to 6 mm from the nerve entrance into the laryngeal wall. The characteristic cells, containing numerous membrane-bound granules, or dense-cored vesicles, are surrounded by bundles of myelinated as well as unmyelinated nerve fibres. Ultrastructurally the cells are very similar to the chemoreceptor cells of the carotid body. Unlike the carotid body, however, the morphometric measurements showed the recurrent laryngeal nerve microglomus to consist of a homogeneous cell type with respect to their content and size of dense-cored vesicles (profile diameter range 20–160 nm, median value 110 nm). Only occasionally was a granulated type of cell with smaller and fewer dense-cored vesicles found.