Question

Briefly write the histological features of abomasum (true stomach) of goat.

Answer 1

The ruminant stomach is divided into the non glandular forestomach( rumen, reticulum ,and the omasum)and the terminal glandular stomach, the abomasum .

Rumen

The Rumen is the largest (by volume) compartment of the ruminant forestomach .The primary function of the rumen is as a storage compartment to facilitate microbial (bacterial and protozoal) fermentation of ingesta.volatile fatty acids are biproducts of this fermentation process and are readily observed across the ruminal mucosa into the circulation ,where they serve as a directly accessible energy source. In addition, microbial digestion of fibrous ingesta begins the digestion necessary to assess nutrients from ingesta that will undergo further breakdown in more distal parts of the gastrointestinal traact. (Eg:abomascum). The Mucosa of the Rumen various regionally but forms variably pronounced leaf like papillae. The nonglandular mucosa of the rumen is composed of keratinizing stratified squamous epithelium. the rumen does not contain a muscularis mucosa.

Reticulam

The reticulam and omasum largely act to further mechanical dissociation of digesta following microbial break down. The mucosal surface of the reticulum is composed of long primary and shorter secondary folds that form a grossly apparent honeycomb- like pattern. As in the rumen the reticular mucosa is composed of keratinizing stratified squamous epithelium. The primary folds (large papillae) of the reticulum contain bundles of smooth muscles with in the lamina propria also referred to as the muscularis mucosa.

Omasum

The mucosal surface of the omasum is composed of large thin leaf like structures called laminae. The microscopic structure of the omasum is similar to the reticulum in that it too contaibs a muscularis mucosa that extends into the laminae. In addition ,the muscularis externa of the omasum extends into the laminae which is unique to this compartment. as in the rumen, the omasal mucosa is composed of a keratinizing stratified squamous epithelium.

Abomasum

The Terminal Chamber of the stomach of ruminants ,the abomascum is functionally and microscopically analogous (identical) to that of the simple stomach of carnivores.