SUPRA-RENAL CAPSULES. 



833 



animals. A portion of fat not {infrequently 

 surrounds the cells of the glandular contents ; 

 and in this manner large dark globules ori- 

 ginate, which completely obscure the enclosed 

 cell. These may especially be seen in the Cat, 

 where they take a clustered arrangement and 

 occupy the limits of the medullary and cor- 

 tical substance. The medullary substance is 

 poor in fat. Hitherto the gland-vesicles have 

 not been made out with certainty in this fatty 

 cortical substance, but they are very distinct 

 in the Hedgehog. 



It yet remains to us to consider the dispo- 

 sition of the blood-vessels, lymphatics, and 

 nerves in the supra-renal capsules of the 

 Mammalia. For this purpose we shall select 

 those of Man. 



Vessels. In the human subject, each 

 supra-renal capsule is supplied with arterial 

 blood by three trunks : by an arteria supra- 

 renalis superior, which is usually present, and 

 comes off as a branch of the phrenica inferior; 

 an arteria supra-renalis media, which is usu- 

 ally double on each side, and arises from the 

 aorta ; and finally, an arteria supra-renalis in- 

 ferior, which is a branch of the renal artery. 

 The further arrangement of the vascular sys- 

 tem has been especially examined by J. Miil- 

 ler*, and Nagel f , whose results have been 

 recently confirmed by Ecker. J 



The numerous small arterial trunks having 

 arrived at the outer surface of the supra-renal 

 capsules, take a different distribution. One 

 part of them immediately pierce the sheath of 

 the organ, and enter its substance ; while an- 

 other portion of them courses for a consider- 

 able distance on the outer surface before be- 

 coming lost in the interior. 



In the interior of the organ itself these 

 small arterial trunks still take a different 

 course. One of these sets of vessels can 

 only be followed for a very short extent 

 in the cortical substance. After a course of 

 scarcely half a line in length, they break up 

 into a capillary network, with long meshes, 

 which encircle the gland vesicles of the cor- 

 tical substance. The other arterial trunks, 

 without giving off any branches, plunge at 

 right angles through the cortical mass into 

 the medullary substance. Here they break 

 up into twigs which, by devious paths, return 

 again into the cortical mass, to end also in a 

 network of capillary vessels. Thus the cor- 

 tical substance possesses a closer capillary 

 network than the medullary mass, a fact which 

 is in conformity with the predominant glan- 

 dular activity of the former stratum. Nagel, 

 in his Essay, has illustrated this distribution 

 of the arterial vessels by beautiful drawings. 



The veins begin at the common margin of 

 the cortex and medulla. They alone con- 

 stitute almost all the vessels of the latter por- 

 tion, since the smallest branches gradually 

 unite to form larger ones, and these finally 

 join to form the vena supra-renalis, which 



* Hildebrandt's Anatomic, herausgegeben von E. 

 H. Weber, 4ter Theil, S. 3.30. 

 f Loc. cit. 

 j Loc. cit. 

 VOL. IV. 



occupies the middle of the supra-renal cap- 

 sule; and, as was stated above, is proportion- 

 ally very large. " Were we able," says Nagel, 

 " to exhibit this venous texture isolated from 

 (he cellular tissue which receives it, the indi- 

 vidual smaller veins opening into the venous 

 trunk on all sides, and at very acute angles, 

 would render it most suitably comparable to a 

 poplar tree." 



Usually there is a single vena supra-renalis 

 for each supra-renal capsule. The right supra- 

 renal vein passes immediately from the gland 

 into the vena cava ascendens ; but the left 

 one forms a longer trunk, which opens into 

 the renal vein. But these statements of 

 Nagel are contradicted by others ; for instance, 

 by Krause, according to whom two or three 

 veins generally leave each supra-renal capsule. 



As far as observations have hitherto gone, 

 this disposition of the vascular system appears 

 to be tolerably constant for all the Mam- 

 malia. 



The lymphatics of the supra-renal capsules 

 are not yet sufficiently known. According to 

 Arnold, there are superficial and deep ones. 

 In animals slain during the digestive act, 

 Ecker could only find the superficial lym- 

 phatics, so that Arnold's statements would 

 seem to be doubtful. The absorbent trunks 

 of the supra-renal capsules unite with those 

 of the kidneys and the internal sexual organs, 

 and they open into the thoracic duct. 



The uncommonly rich supply of nerves 

 possessed by the supra-renal capsules consti- 

 tutes a very striking phenomenon, and one 

 which finds no parallel in any cognate organs. 

 In Man, these nerves arise from the caeliac 

 and renal plexuses in the form of numerous 

 and proportionally large trunks. It is chiefly 

 through Ecker that we have become ac- 

 quainted with the further course of the nerves 

 in the interior of the organ. Larger and 

 smaller branches of nerves perforate the cor- 

 tical substance, usually contained in the bun- 

 dles of its areolar tissue, or accompanying its 

 arterial vessels, but giving off no primitive 

 fibres. Only in the medullary substance do 

 the trunks of nerves break up into bundles of 

 fibres. The neighbouring bundles often ex- 

 change their nerve-fibres with each other, so 

 that, in this way, they form a dense micro- 

 scopic nervous tissue. It would seem that, 

 in the human subject, no ganglion corpuscles 

 are present in this sympathetic nerve tissue ; 

 but, in the Horse, in whom the supra-renal 

 corpuscles are yet richer in nerves than they 

 are in man, some ganglion corpuscles may be 

 seen on the nervous trunks of the tissue. 

 But one must be especially careful against 

 confounding gland-cells of the organ with 

 these ganglion corpuscles, which they super- 

 ficially resemble. This rich supply of nerves 

 seems only to pertain to the supra-renal cap- 

 sules of the Mammalia ; in all the other Ver- 

 tebrata, whose supra-renal capsules, as will be 

 forthwith stated, are very similarly constituted, 

 it is completely wanting. On this account, it 

 becomes exceedingly difficult to state what 



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