The vasculature of 22 small colons from dead adult ponies was perfused with latex or barium sulphate solution. The vascular anatomy was studied by use of dissection and alkali digestion of the latex specimens and microangiography of the barium sulphate-perfused specimens. The small colon is supplied by the caudal mesentric artery. The left colic artery arises from the caudal mesenteric artery, which then becomes the cranial rectal artery. Branches from the left colic and cranial rectal arteries form anastomosing arcades that become narrower distally along the length of the small colon. From these arcades arise terminal arteries, which enter the small colon wall and give rise to a subserosal, an intermuscular, and a large submucosal plexus, with frequent anastomoses between them. The venous drainage closely parallels the arterial supply, except near to its origin from the portal vein, when the left colic vein and caudal mesentric vein are separate from the corresponding arteries.

Microvascular circulation of the ascending colon in healthy horses was studied using microangiography, light microscopy, and scanning electron microscopy. The pelvic flexure with 30 cm of ventral and dorsal colon attached was removed from 14 adult horses immediately after horses were euthanatized. The lumen was flushed with warm water, and this section of the ascending colon was placed in a 37-C bath of isotonic NaCl. In sections from 8 horses, colic vessels were perfused with a radio-opaque medium for microangiography. After angiographic evaluation, tissue sections were prepared for light microscopic observation, using standard histologic methods. In sections from 6 horses, injection replicas were made by perfusing the vessels with 2 types of plastics. The results of microangiography, light microscopy, and scanning electron microscopy of vascular replicas were correlated, providing acomprehensive documentation of the microvasculature of the ascending colon at the pelvic flexure. Arteries branched from mesenteric colic vessels approximately every 2 cm toward the colonic tissue. Immediately after branching, arterial vessels formed an anastomotic plexus, the colonic rete. However, each branch from the colic vessel eventually continued into the colonic tissue. A second set of vessels originated from the colonic rete and supplied the mesenteric lymph nodes. Arterial vessels penetrated the tunica muscularis into the sub-mucosa 3 to 4 cm toward the antimesenteric border forming a submucosal vascular network. From the submucosal arterioles, branching took place at right angles to supply the mucosal capillaries. Capillaries surrounded the colonic glands and anastomosed at the luminal surface, forming a superficial luminal honeycomb-appearing vascular plexus. Venules, sparsely distributed, drained the superficial plexus. Arterial venous anastomoses were not observed within the mucosa.

The distribution of portal veins within the liver in 30 Korean native cattle were observed. Vinylite solution was injected into portal veins of eighteen specimens for cast preparation. The angiography was prepared in twelve specimens by injecting 30 % barium sulfate solution into portal veins, and then radiographed on an X-ray apparatus (Shimadzu 800 MA 120 Kvp). The Vena portae was divided immediately upon entering the liver into a very short Truncus dexter venae portae (14.75 +- 4.86 : 6.9-23.1mm) and a long Truncus sinister venae portae (94.16 +- 9.62 : 110-150 mm). The Truncus sinister venae portae runs of first in the long axis of the liver from the porta hepatis toward the left lobe. At the boundary between the quardate and left lobes it bends sharply 50 to 80 degrees toward the Incisura ligamentum teretis, and after a course of 36.5 to 54.3 mm between the quadrate and left lobes, ends abruptly. The Truncus sinister venae portae is divided for description into the Pars transversa, from the Porta hepatis to the flexure, and the Pars umbilicalis, from the flexure to the end. The branches of Venae portae were Ramus ventralis lobi sinistri, Ramus intermedius lobi sinistri, Ramus dorsalis lobi sinistri, Ramus lobi quadratti, Ramus ventralis lobi dextri, Ramus intermedius lobi dextri, Ramus dorsalis lobi dextri, Rami processus caudatorum and Rami processus papillarum. The Ramus intermedius lobi sinistri arose from the left surface of the Pars umbilicalis, and was origined on the common trunk with Ramus dorsalis lobi sinistric (3 cases, 10 %) or Ramus ventralis lobi sinistri (3 cases, 10 %). The Rami lobi quadratii consisted of the vein (15 cases, 50 %) or two veins (15 cases, 50%), and was observed on the arched-shaped at 2 cases (6.6 %) of the liver. The Rami processus caudatorum consisted of one vein (28 cases, 93.3 %) or two veins (2 cases, 6.6 %). The former were formed common trunk with R. dorsalis lobi dextri (7 cases, 23.3 %) or R. ventralis lobi dextri (2 cases, 6.6 %)