. Diseases of the heart and thoracic aorta. -posed, the aneurism is called dissecting. A combination ofthese different forms is not unfrequently met with (see and 269), in which there are three aneurisms, one a goodexample of the globular or fusiform variety, and the othertwo sacculated). Etiology and Pathology.—The great causes of aneurism ofthe thoracic aorta, indeed of all internal aneurisms, d^re, firstly,local weakness of the arterial wall, and secondly, increasedarterial blood pressure. The most common cause of local weakness of the aorticwall is chronic endarteritis (atheroma),
. Diseases of the heart and thoracic aorta. -posed, the aneurism is called dissecting. A combination ofthese different forms is not unfrequently met with (see and 269), in which there are three aneurisms, one a goodexample of the globular or fusiform variety, and the othertwo sacculated). Etiology and Pathology.—The great causes of aneurism ofthe thoracic aorta, indeed of all internal aneurisms, d^re, firstly,local weakness of the arterial wall, and secondly, increasedarterial blood pressure. The most common cause of local weakness of the aorticwall is chronic endarteritis (atheroma), but any degenerationor inflammation either of the internal, the middle, or theouter coat, will produce local weakness, and will thereforepredispose to the formation of aneurism. Degeneration of the Occasionally the patient survives for a few days. ^ Aneurisms of the abdominal aorta are not described in this work, but thisspecimen is represented because it is more typically saccular than any aneurism ofthe thoracic aorta which I Fig. 267. Aneufism of the Abdominal Aorta, involving the origins of the cseliac axis, superior mesenteric and renalafteries. (Smaller than the actual specimen—a dried preparation. Size of drawing, 6^ x 4^ in.;size of specimen, 8^ x 7-^ in.). a, descending thoracic aorta; b, abdominal aorta at its bifurcation; c, inferior mesentericartery; d, the right, and e, the left kidney; f, the upper sac of the aneurism, which involv-otithe origin of the cseliac axis; g, the lower sac from which the main branches of the renaarteries spring; h, h, the ureters.
Size: 1374px × 1819px
Photo credit: © The Reading Room / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1800, bookdecade1880, booksubjectheart, bookyear1884
