Embryonic differentiation of the rectum of one humped camel (camelus dromedarius): A histomorphology

Abstract

A research was conducted on the rectum of 35 foetuses of the one-humped camel collected from the Sokoto metropolitan abattoir, over a period of five months at different gestational ages for histomorphological differentiation. The approximate age of the fetuses was estimated and categorised into first, second and third trimester. Gross observation, result and discussion were critically highlighted, Histological observation of the tissues in this study revealed a complete structure of the tubular organ. The rectum was found to consist of four layers namely: Tunica mucosa, Tunica sub mucosa, Tunica muscularis and Tunica serosa. The epithelium of the Tunica mucosa was stratified squamous epithelium with varying degree of stratification along the length at first trimester and transformed to low columnar /cuboidal epithelium at second trimester. At third trimester, the epithelium was simple columnar epithelium. The lamina propria mucosa was found absent at first trimester but prominent at second and third trimester. The Lamina mascularis mucosa was found prominent at third trimester but not identified at first and second trimester. At first trimester of age, tunica submucosa was prominent while at second trimester, it consisted of connective tissue cells and fibres scattered all over the layers with preliminary blood vessels. The cells and fibres were undifferentiated at this stage. There was no evidence of secretory cells within the layer. At third trimester of age, the connective tissues and blood vessels were found prominent throughout the length of the rectum. The tunica muscularis of camel rectum consist of two band of smooth muscle sandwich with skeletal muscle layers. At first trimester this layer did not differentiate into these three zones but only longitudinal orientation of smooth muscle layer. At second trimester, the layers of three zones with clear demarcation was observed, while at third trimester, the skeletal muscle layer appeared to be much thicker than the two longitudinal smooth layer. A thin layer of connective tissue comprising of undifferentiated cells lined the rectum externally was observed in all the stages of development. Based on the above findings, it showed that development of the camels rectum was morphological in succession over a period of time.

Key words: Camel, rectum, embryonic differenciation, histomorphology.