Modern concepts about the carotid glomus morphology

The carotid glomus (glomus caroticum) is a chemoreceptor organ of the paraganglionic system, functionally stimulated by hypoxia, hypercapnia and acidosis. The relevance of its study is due to its ability to regulate blood pressure and heart rate. The importance of studying the structure of this organ is due to carotid endarterectomy in atherosclerosis of the internal carotid artery with its stenosis in combination with symptoms of cerebrovascular accidents. Significant anatomical variability of its innervation and blood supply, rapid postmortem pathomorphological changes and tissue predisposition to artifacts during the preparation of histological preparations complicate the interpretation of the results of morphological studies. The objective of the review is to present material combining information on the structure of the carotid glomerulus at the organ, tissue, cellular and subcellular levels of its organization. The following scientific databases were used to search for information: PubMed, Scopus, Web of Science, Europe PubMed Central, HubMed, e-Library.ru, CyberLeninka, Google Academy. The keywords in the search were carotid body, carotid glomus. Of the 44 valid scientific publications, 9 were written by Russian scientists, 35 - by foreign authors. Analysis of the structure of the glomus at the macroscopic level indicates variability in the number, symmetry of location, and shape of this organ. Light microscopy allowed us to classify it as an organ of the parenchymatous type of structure with the presence of a structural and functional unit - the glomerulus. Immunohistochemical research helped to verify the parenchyma cells and classify them into two types, and ultrastructural analysis helped to form an idea of the contents of these cells and their intercellular interactions. Based on the data obtained, the relevance of further study of age-related and reactive changes in the carotid glomus, as well as its role in the development of arterial hypertension, bronchial asthma, chronic obstructive pulmonary disease, head and neck tumors and other pathological processes associated with its function is substantiated. Morphological studies of the carotid glomus can provide new facts for the development of human morphology, increase the effectiveness of therapy for patients with diseases of the cardiovascular, respiratory, and nervous systems. For this, it is necessary to clarify some key points, in particular, the morphology of the supporting cells of the second type, to determine in more detail the types of intercellular contacts in the glomerulus, and to solve classification problems in the description of the main cells of the glomerulus.