from The American Heritage® Dictionary of the English Language, 5th Edition.
- noun A small body, such as the carotid body, consisting of an anastomosis between fine arterioles and veins and supporting structures.
from The Century Dictionary.
- noun A coil of choroid plexus extending into either lateral ventricle of the brain.
- noun A coil of blood-vessels projecting into the body-cavity, or cœloma, in the region of the pronephros in the embryos of the lower vertebrates. (See cut in next column.)
from The American Heritage® Dictionary of the English Language, 4th Edition
De Castro suggested rather that the glomus was an organ whose function was to react to variations in the composition of the blood, in other words an internal gustatory organ with special «chemo-receptors».
Behind the angle of bifurcation of the common carotid artery is a reddish-brown oval body, known as the glomus caroticum (carotid body).
De Castro, however, in 1927 demonstrated that the anatomy of the glomus could in no way be compared to that of the suprarenal medulla.
The glomus consists of a small mass of very fine intertwining vessels arising from the internal carotid and enclosing various different types of cells.
It seems likely however that this depressor nerve mechanism plays only a small part in the respiratory reflexes produced by a marked lowering of oxygen contents and that the essential pathway is via the glomus caroticum.
In 1933, Heymans and Rijlant demonstrated that these potentials were of two different kinds, the greater being produced by blood pressure in the sinus, the other by chemical stimulation in the glomus.
In certain cases (lobeline, nicotine, cyanide, sulphide, etc.) the drug acts on the glomus, in others (e.g. Cardiazol) it acts by central stimulation and again in other cases (e.g. Coramine) it acts centrally and peripherally.
Other experiments showed that Heymans's concepts on the important role played by the glomus in the reflex control of respiration by the chemical composition of the blood were undoubtedly correct.
Heymans not only discovered the role, hitherto quite unknown, of certain organs (glomus caroticum and glomus aorticum), he also greatly enlarged our field of knowledge concerning the regulation of respiration.
Since the end of the 18th century we know of the existence of a curious structure in the region of the sinus, the glomus caroticum or carotid body which, in man, extends over only a few millimetres.