Structural Differences Between Distended and Collapsed Arteries

Abstract

Arteries distended normally with blood were removed from dogs in vivo using a special double hemostat. Some of their anatomic features were compared with those of similar collapsed vessels conventionally obtained post-mortem. An intimal layer was not found in distended arteries from young, healthy dogs, the endothelium being tightly compressed against the internal elastic lamina. An intima was formed in some collapsed vessels from the same animals, however. The thickness of the layer was increased in arteries from aging dogs, and in the presence of degenerative changes in the wall. A possible mechanism for the formation of the intima is suggested.