Ultrastructural characterization of the intestine of the Eurasian common moorhen using scanning electron microscopy and light microscopy.

The present investigation focused on the morphological features of the intestine of Eurasian common moorhen by the aid of scanning electron microscopy and histological, morphometric, and statistical examinations. The intestinal villi were varied in shape along the intestinal tract; the duodenal villi were elongated and twisted, the jejunal villi were tongue-like, the ileal villi were cuboidal, and the cecal villi were tongue-like and finger-like at the base and body of the cecum. While at the apex of the cecum, it appeared as corrugated longitudinal folds and the rectal villi appeared as columns. The microvilli were present as projections on the surface of villi of the small intestine and the base of the cecum. While at the body and the apex of the cecum, the microvilli appeared as threads and as brush hairs on the rectal villi. The duodenal, jejunal, ileal, cecal, and rectal villi were lined by simple columnar epithelium with goblet cells. The submucosal layer of small intestine consisted of connective tissue fibers along the intestinal tract, but it was absent at the base of the cecum. The tunica musculosa consisted of single longitudinal layer of smooth muscle fibers in the duodenum and rectum. While in the jejunum, ileum, and cecum, it was composed of single circular layer of smooth muscle fibers. The thickness of the tunics differed among the intestinal parts.