The obscurity of most of the diseases of the blood vessels makes their determination very difficult until an accident, perhaps of seri ous character, has occurred. We are able to detect hardening of the arteries by the physical characteristics and the recent studies in blood pressure are clearing up important questions in other particulars, but there remains much to be found out before the pathology of the blood vessels will be entirely elucidated.
Arteries may have acute or chronic disease, with or without inflammation. When an artery is inflamed its calibre may be diminished, or even obliterated (endartentis obliterans) or it may be increased (endarteritis deformans). Arterial diseases which are not inflammatory may be degenerative, fatty, amyloid or calca reous. Tuberculosis rarely attacks the struc ture of the arteries, and the very common con dition known as atheroma, very often associ ated with syphilis, is a chronic inflammation with degeneration. Atheroma often terminates in ulcer with deposits of salts of lime in its vicinity.
Acute inflammation of an artery may be caused by the irritation, and possibly the in fection, of an embolus or plug, from the con sequences of ligation, or by the extension of a neighboring suppurating wound or ulcer. Inflammation of the arteries with enlargement of calibre is most often seen in the aged, the aorta being frequently attacked. With it may
be associated atheroma, fatty degeneration or calcification. Fatty degeneration also usually accompanies atheroma and calcification. It is probable that the veins are less susceptible to disease than the arteries, though there are acute and chronic forms of phlebitis. Injuries to veins are rather more frequent than to arter ies on account of the exposed position near the surface of those which constitute the super ficial system of veins. They are also very subject to the formation of thrombi because of the fibrin in their walls. Acute phlebitis may be adhesive or suppurative and is one of the accompaniments of an infectious process in pregnancy and child-bed. A suppurative phlebitis may be an extension of a suppurating process in tissues adjacent to a vein which is attacked, and in py-emia the veins are filled with pus. An adhesive inflammation in veins may result from traumatism or from some form of poison in the blood. The veins may be the seat of calcification and of ulcers as well as the arteries.
Tuberculosis is probably more frequent in veins than in arteries, especially when it results from an extension of the disease in the neigh boring lymphatics. See ARTERIES; ATHEROMA ; CAPILLARIES; GOUT; PYJEMIA ; RHEUMATISM; SYPHILIS. ANDREW F. CURRIER, M.D.