Quantitative histological changes of tunica media layer of brachiocephalic artery in pigeon

摘要

In birds, the brachiocephalic artery is the second branch of aorta which gives rise to the common carotid and subclavian arteries. Purpose of the present study was to compare the relationship between some segmental structural characteristics of the tunica media (the number of elastic layers) of the brachiocephalic arteries wall of pigeon in different ages of both sexes using histological analysis. Eighteen pigeons, divided into three groups of six pigeons aged 20, 50 and 120 days old in both sexes. After preparation of histological sections of brachiocephalic arteries, the samples stained with haematoxylin and eosin stain for general histological study and orcein stain for elastic layers. In the male pigeons, the mean numbers of elastic layers of the tunica media in the right side of brachiocephalic wall on day 20 was more than day 120 and on day 120 was more than day 50 (P0.05). The mean of numbersof elastic layers of tunica media of the brachiocephalic arteries in left side between both sexes on days 20 and 50 was not significantly different, and in females was more than males in the right side on day 50 and both sides on 120 (P<0.05). In conclusion, the presence of vasa vasorum in the tunica intima of brachiocephalic artery as a new finding and the considerable numbers of elastic layers of tunica media can be due to the flight in pigeon.