Aortic aneurysm. Artwork from Jean Cruveilhier's medical textbook Anatomie pathalogique du corps humain, published 1835. The two large illustrations are views of an aortic aneurysm (brown, centre), or bulging of the aorta caused by a weakening of its outer wall. Local blood pressure inflates the weakened artery. The heart has been dissected away to reveal the aneurysm. Aneurysms can burst at any time, causing instant death, and the larger the bulge the greater the danger. The third, smaller illustration on the right is a cross-section of myocardium, or heart muscle. Cruveilhier (1791- 1874) was an eminent French anatomist.