Light and scanning electron microscopy of the small intestine of goat (Capra hircus)

Abstract

Sections from duodenum, jejunum and ileum of local breeds of goat (Capra hircus) were studied histologically using light and scanning electron microscopy. The wall of goat small intestine is composed of typical layers: lamina epithelialis mucosae, lamina propria, lamina muscularis mucosae, tunica submucosa, tunica muscularis and tunica serosa. Small intestine villi were covered by a simple columnar epithelium with goblet cells and simple tubular glands, the crypts of Lieberkühn, containing paneth cells were observed between the villi. The presence of mucus was extensive in the duodenum and the number of goblet cells was highest in the duodenum. The lamina propria consisted of loose connective tissue rich in blood and lymphatic vessels. The lamina muscularis mucosa was presented as a thin layer of circular smooth muscle fibers at the base of the crypts. The submucosa consisted of conjunctive tissue containing blood and lymphatic vessels. The tunica muscularis consisted of the typical inner circular layer and outer longitudinal layer of smooth muscle. The tunica serosa was the thin, outermost small intestine layer that consisted of a very small amount of conjunctive tissue covered by mesothelium. The submucosa was devoid of glands in all three small intestine regions. Scanning electron microscopy showed finger shaped villi in the jujenum, tongue shaped in ileum, leave like in duodenum; the villus has corrugated surface. The corrugations are deep, irregular clefts cutting into the side of the villus. The corrugations are scarce in the duodenum, few in jujenum and numerous in ileum. The surface of villi presents the goblet cell orifices.

Alimentary System of Native Goat Breeds of Pakistan

“…Number of mucous-producing goblets cells increases anterior to posteriorly. The columnar epithelium has a brush border on the top and the mucosa has crypts of Lieberkuhn [62][63][64]. Columnar cells, Paneth cells, and goblet cells are present in the crypts [24].…”

“…The tunica submucosa is formed by CT, mononuclear cells, having fine blood capillaries along with CT cells, elastic, collagen, and reticular fibers. In duodenum, there are Brunner's glands present in the submucosa which secrete alkaline mucus secretions protecting the intestinal mucosa from the acid released out from the stomach and the viscous mucus lubricates the gut contents [61,63,65]. Tunica muscularis thick layer comprising smooth muscle layers similar to the layers present in the mucosa.…”