Morphological study on the colon of the ostrich (struthio camellus)‎

الملخص EN

The colon of twelve ostrich aged from 1.5 - 5 years old were used in this study.

The colon of the ostrich is very long of approximately 14 meters; it was divided into proximal, middle and distal distinct segments.

The proximal segment appeared grayish and saccuolated, its average length was 6.35 meters, with relatively short mesentery and situated in the right dorsal part of the abdomen.

Its mucous membrane formed annular mucosal folds of different height and condensation along its length.

The middle segment was thin walled and lighter, it was about 7.5 meters long and arranged in garland- like coils at the edge of long mesentery, it occupied the left caudodorsal part of the abdomen, its mucosal folds were irregular, in the form of short segments, at its termination the mucosal folds became fewer and form slightly raised lines.

The distal segment was short, about 30 cm, it was projected in the cavity of the coprodium for a distance about 2.5 - 3 cm and opened by a narrow opening like a sphincter, its lumen has many longitudinal mucosal folds.

The proximal segment was supplied by the proper colic artery which originated from the cranial mesenteric artery and gave many colic branches, their collateral branches anastmosed at the mese-nteric border forming anastomotic arcades.

Several straight twigs bypassed to each side of the colon through the mucosal folds circling to the anti mesenteric border.

The middle and the terminal segment were supplied by the caudal mesenteric artery, it gave off 10-12 long branches get the way into the long mesentery toward the mesenteric intersection of the distal segment, each branch provide 4 subdivision before, the last subdivision, anastmosed forming the anastomotic arcades.

Histological finding revealed that, the ostrich colon was lined by simple columnar epithelium; it was thrown into the lumen forming occasionally branched intestinal villi in the distal segment.

In all regions it was studded with goblet cells that exhibited strong PAS positive on the surface epithelium and the neck of intestinal crypt and strongly alcian blue positive at its bottom in the proximal segment of the colon.

In the middle segment it showed alternate positive reaction along the intestinal crypts to PAS/AB and exhibited strong AB positive reaction at the bottom.

In the distal segment goblet cells showed strong AB positive reaction along the intestinal crypt.

The intestinal crypts increased in depth, width and number caudally.

Leukocytic infiltration in the lamina propria was more abundant toward the distal segment and solitary lymphatic nodules were observed only in the distal segment.