This study was carried out on eight adult birds of each of the chicken (walking bird), duck (swimming bird) and p < span style="text-decoration: underline;">igeon (flying bird). Blood vessels develop according to the particular requirements of the region supplied.
Clearly distinguished differences of diameter, wall thickness and cross sectional area of the axillary and ischiatic arteries were recorded between the studied birds. There is a correlation between the diameter of the artery, cross-sectional area of its lumen as well as its wall and the mode of locomotion. The axillary artery in pigeon has a larger diameter than that in duck and chicken. On the other hand, the ischiatic artery in duck and chicken has a larger diameter than in p < span style="text-decoration: underline;">igeon. The axillary artery in pigeon has a wider lumen and a thinner wall than those of the ischiatic artery, but in chicken the latter artery has a wider lumen and a thinner wall than the former one. The present work indicates also that the amount of the elastic tissue in the tunica media of the studied arteries increases corresponding to the particular needs of the region supplied. The axillary artery contains abundant elastic tissue in pigeon compared to that in duck and chicken. On the contrary, the ischiatic artery has the largest amount of the elastic tissue in duck followed by chicken then pigeon.