Alterations of the internal elastic membrane in juvenile human arteries.

Quantitative changes in the internal elastic membrane (IEM) were studied in human arteries from different location in 31 males and 31 females, using an eight-criterion classification system. The IEM involvement shows a sex-dependent increase with age, and is more pronounced in arteries known to exhibit a more intensive atherosclerotic involvement. It seems that the IEM changes represent a true ageing phenomenon, which is sometimes influenced to a various degree by the atherosclerotic process.