an·eu·rysm also an·eu·rism (ănyə-rĭz′əm)
An abnormal, blood-filled sac formed by dilation of the wall of a blood vessel or heart ventricle, most commonly the abdominal aorta and intracranial arteries, resulting from disease or trauma to the wall, as in atherosclerosis.
[Middle English aneurisme, ultimately from Greek aneurusma, from aneurein, to dilate : ana-, throughout; see ANA- + eurus, wide.]
an′eu·rysmal (-məl) adj.
(click for a larger image)aneurysm
left: normal abdominal aorta
right: abdominal aortic aneurysm
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