Histomorphological Development Study of Cecum in Local Awassi Sheep Fetuses (Ovis Aris): Prenatal Periods

Abstract

This study was conducted at Al-Qasim Green University/College of Veterinary Medicine, Anatomy and Histology Branch. The experiment was designed to study the cecum of Awassi sheep fetuses: prenatal periods. Samples (30 male and female samples) were collected from healthy females uterine and divided according to age groups into four groups by crown rump length formula (CRL) for the prenatal stage. In the first age group (50-55), the cecum was in the process of development, as it was not distinguished visually. In the second age group (70-75 days), it was a small protrusion located between the ileum and the beginning of the ascending colon. With advancing age, the third group, which includes two ages in the third trimester of pregnancy, we found that the cecum was completely formed in (100-105) days and at (130-140) days of gestation. Also, upon histological study, we found that the wall of the cecum consists of four layers, as in the rest of the parts of the digestive system, and is lined with an epithelial layer surrounded by a layer of connective tissue. It is supportive of the epithelial tissue. We also found tunica submucosa constantly devolving with age, as it is mesenchymal cells in the first stage of intrauterine life and begin to transform into connective tissue with the presence of fibers and collagen (tunica submucosa) as a result of these cells transforming into spindle cells to form the inner muscle layer, as well as tunica muscularis externa. The latter is surrounded by loose connective tissue that contains a few collagen and elastic fibers surrounded by mesothelial cells (tunica serosa) that contain blood vessels to support development in the inner layers.