THE DUCTLESS GLANDS. 



OKIGINALLY BY THE LATE D. J. CUNNINGHAM, F.E.S., 



Late Professor of Anatomy, University of Edinburgh ; 



EEVISED AND EEWRITTEN BY A. C. GEDDES, M.D., F.E.S.E., 



Professor of Anatomy, M^Gill University, Montreal. 



THE title, the ductless glands, denotes a group of organs whose function is to 

 elaborate a special product and to discharge it into the blood or lymph. These 

 activities constitute the act of internal secretion. 



The group includes the hypophysis and the pineal body, which are described with 

 the brain ; the suprarenal glands, which are compound organs and are the principal 

 representatives of two important systems of glandular tissue called respectively the 

 chromaphil and cortical systems ; the glandule caroticse, which are outlying parts 

 of the chromaphil system ; the thyreoid and parathyreoid glands, and the thymus, 

 which are developed from the entodermal lining of the embryonic pharynx ; the 

 spleen and the glomus coccygeum, which are associated with the circulatory system. 



Physiologically, the liver, pancreas, gastric and intestinal mucous membranes ; the kidneys, 

 prostate, and testes ; the uterus, ovaries, corpus luteum, and possibly some other organs form 

 internal secretions, and act therefore as "ductless glands" in addition to fulfilling their more 

 obvious functions. Anatomically, the lymph and haemo-lymph glands are "ductless glands," 

 but it is not customary to speak of them as such. 



1. THE CHEOMAPHIL AND COETICAL SYSTEMS AND THE 

 SUPEAEENAL GLANDS. 



A. THE CHROMAPHIL SYSTEM. 



(SYNONYMS : Chromophil, Chromaffin, Phceochrome, Phaochrome System.) 



The chromaphil system is composed of a number of discrete masses of tissue 

 which produce and discharge adrenin (Isevo-adrenalin, C 9 H 13 N0 3 (Aldrich)). The 

 name chromaphil is given to the tissue because the cells forming it contain 

 granules which, in the presence of chromium salts, stain to any tint between 

 bright yellow and dark brown. The distribution of the masses of tissue forming 

 the system is shown in Fig. 1053. There are (i.) a series of isolated masses, the 

 paraganglia, associated singly or in groups with the ganglia of the sympathetic 

 nervous system, (ii.) a number of masses, chromaphil bodies of the sympathetic 

 plexuses (aortic bodies) in close relation to the abdominal sympathetic plexuses, 

 (iii.) the glandulse caroticse, and (iv.) the medullary portions of the suprarenal 

 glands. 



(i.) The paraganglia are rounded masses of chromaphil tissue, 1-3 mm. in diameter, 

 placed inside, half inside, or immediately outside the capsules of the ganglia of the 

 sympathetic system. Typically one paraganglion, exceptionally a pair of paraganglia, is 

 associated with each ganglion of the gangliated trunks and with each ganglion of the 

 cceliac, renal, suprarenal, aortic, and hypogastric plexuses. Inconstantly, paraganglia 



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