Histodynamic observation of blood vessel in adult human and three kinds of mammalian

Aim: To observe the structure and its evolvement of the wall of large and medium-sized blood vessels of normal adult dog, rat, rabbit, and human, and study the histodynamic process of blood vessel. Methods:The paraffin sections of blood vessels from 5 adult human autopsies, 5 dogs, 12 rats, and 3 rabbits, stained with HE, were observed under light microscope. Results: The walls of large and medium-sized blood vessels of adult human, dog, rat, and rabbit were commonly composed of tunica intima, tunica media, tunica adventitia, and tunica theca. On the surface of tunica intima, homing and innerration of hemangioblast and aggradations surface endothelial conversion could be found. In the region between tunica intima and tunica media, the evolving serial from the cells of tunica intima to smooth muscle cells of tunica media could be observed. The degradative serial of smooth muscle could be found in the region between tunica media and tunica adventitia. The tunica theca originated from nervous tissue appeared in the region outside tunica adventitia.Conclusion: The walls of large and medium-sized blood vessels of normal adult dog, rat, rabbit, and human are mainly evolved by homing and innerration of tunica intima cells originated from hemangioblast. The tunica intima cells are evolved to form smooth muscles of tunica intima, and the smooth muscles are degraded to form tuica adventitia. Tunica theca is the evolving remnant of blood vessels originated nervous tissue, which could evolve into vasa vasorum and fat tissue.