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Suprarenal Capsules

bodies, capsule, kidney and renal

SUPRARENAL CAPSULES, two small, ductless glandular bodies situated at the front portion of the upper end of each kidney. They are generally classified with the spleen and similar structures as ductless glands. Each suprarenal capsule exhibits a yellowish color. That of the right kidney is somewhat of trian gular shape, the left being of somewhat cres centic form. In some cases these bodies may be hardly recognizable on account of their minute size. Their average weight is from one to two drams. Each capsule is connected to its kidney by areolar tissue only, no vascular or other connections existing between the glands; and neither capsule has any outlet or excretory duct. They lie behind the peritoneum, or lin ing membrane of the abdomen, the front sur face of the right suprarenal capsule being in contract with the under surface of the liver, the same surface of the left being in with the pancreas and spleen. The capsules derive their blood from the aortic, renal and phrenic arteries, and return their blood by the supra renal vein, which receives its blood from the net-work of the medullary portion, and also partly from the cortical substance of the organ. The nerves of the suprarenal capsules are nu merous, and are branches of the solar and renal plexuses and of the phrenic and pneumogastric trunks. The suprarenal capsules are present in

all mammals, and are largest in Rodentia, and smallest, proportionally, in the whales, in which they are lobulated or divided into lobes. In birds they are of small size, and exist generally on the inner aspects of the kidneys. In sharks they exist as a single, long, lobular organ lying behind the kidneys; and in frogs and toads they appear as yellowish patches on the kidney. They are also lobular in sturgeons and other fishes, and in newts and Urodela generally. That these bodies may have some important function to discharge in connection with the blood-circulation of the embryo is a highly rea sonable suggestion; but further than this gen eral statement physiology cannot certainly pro ceed. Facts of much interest in connection with these bodies, however, have been observed in cases of Addison's disease (q.v.). The ac tual diseases to which these bodies are liable consists of hypertrophy or enlargement, atrophy or wasting, tuberculous degeneration, fatty dis ease and occasionally cancerous infiltration.