[The vascular system of the intestines of Gallus domesticus]

The vascular system of the chicken intestine was investigated by corrosion cast, light and electron microscopic methods. In the intestinal villi the "Fontainentyp" is present with a single arteriole rising to the apex and draining into subepithelial capillaries. Occasionally ramifications of the arteriole occur in the upper third of the villi. Another variation is splitting of the arteriole into a capillary net at the base of the villi in the caeca between the regions with and without villi. At the tip, at the margins and at the base of the villi the capillaries fuse into venules, which proceed to the inside and empty into veins. At the base above the propria they form a superficial net with connecting veins arising to an inferior venous plexus below the region of crypts. The submucosal collecting veins descend from short vascular truncs, which originate from the inferior plexus and cross the muscularis mucosae. Elements of a vasoregulatory system like arterio-venous marginal loops, submucosal arterio-venous anastomoses, sphincter-arteries, precapillary sphincters and sphincter-veins well known in the literature are not found in the intestine of the domestic chicken. Therefore arterioles, capillaries and muscle bundles concentric around the veins in the villi seem to take over this function.