CAROTID GLAXD (GLOMUS GAROTIGUM). 153 



alveoli which, like those of the thyroid, are filled with a colloid 

 substance. Sometimes these alveoli are lined with ciliated 

 epithelium. 



There is a close relation between the glandular elements and 

 the blood capillaries. A dense network of vessels surrounds 

 all the gland alveoli. The glandular nature of the organ 

 has been further proved by physiological experiments. The 

 internal secretion seems to have an important influence on the 

 organism as a whole. 



8. CAROTID GLAND (GLOMUS CAROTICUM). 



The carotid gland is a structure the size of a grain of 

 corn, situated, in man, at the bifurcation of the common 

 carotid artery. It is associated closely with the vessel wall, 

 and is surrounded by a connective- tissue capsule which sends 

 strands of tissue into the organ. The organ thus is divided by 

 three connective-tissue septa into follicles, which are usually 

 small round masses of cells, the so-called cell balls (Zellballen) 

 of Schaper. These follicles, or cell balls, are made up of cells 

 containing much protoplasm and resembling epithelial cells. 

 They are polyhedral or round, and seem to be associated closely 

 with the blood capillaries. They are apparently of connective- 

 tissue origin, and are arranged in small groups in the meshes 

 of a connective-tissue network. The true nature of this con- 

 nective tissue has never been determined. In all probability 

 it is largely true reticulum. In advanced age the cell groups 

 break up, and there is a marked increase in the connective 

 tissue and blood-vessels (Schaper). 



1 The carotid gland is supplied very richly with blood-vessels. 

 A branch from the carotid artery enters the gland and breaks 

 up into many small branches, each of which supplies one 

 follicle. The capillaries formed by division in the follicle 

 anastomose and make up a dense plexus, which is connected at 

 the periphery of the follicle with small veins. These join with 

 veins from other follicles, and form on the surface of the gland 

 a venous plexus. 



Numerous medullated and non-medullated nerve-fibres are 



