Supra-renal Capsules

Supra-renal Capsules, two small, flattened, glandular bodies of a yellowish colour, situated, as their name implies, immediately in front of the upper end of each Kidney (q.v.). In weight they vary from one to two drachms. They belong to the class of ductless glands, and on making a perpendicular section each gland is seen (like the kidney) to consist of cortical and medullary substance, surrounded by a fibrous investment which is intimately connected with the subjacent structure, and is continuous with the fibrous stroma which pervades the organ. In the cortical portion the cells are arranged in rows or columns, and are polyhedral in shape, while in the medullary portion the stroma forms a network, in the meshes of which groups of cells of more irregular outline are found. The blood-vessels and nerves of the glands are exceedingly numerous. Their function is extremely obscure, and with regard to it nothing is positively known. In 1855, however, Dr Thomas Addison showed that a rare form of disease, characterised by progressive debility and emaciation, with increased pigmentation of the skin (known as Addison's Disease, or Bronzed Skin), is associated with disease of these organs. It has since been proved that only one particular form of degeneration leads to this result; cancer, sarcoma, &c. have no similar consequence.