Animal Science Frameworks Presentation Unit 3 Mr. Sullivan

Ruminant and Monogastric Ruminants have a four- part stomach Monogastrics have a simple stomach or sometimes its called one- stomached

The Forestomach Components of Ruminant Animals Rumen The rumen is an enormous space filled with chewed and half-chewed materials the cow has ingested, swallowed, regurgitated, and swallowed again (often several times). The cow who "chews her cud" is methodically grinding the food into smaller and smaller bits, allowing the symbionts more and more surface area on which to work.

Reticulum It consists of bands of smooth muscle which run through the tops of the ridges of the honeycomb, and which are more or less isolated from the lower levels, nearer the wall.

Omasum This organ has a number of colorful layman's names applied to it, among them "many-plies" and "the butcher's Bible," the latter referring to its similarity to the leaves of a book in gross appearance.

Abomasum The true glandular stomach of ruminants. Its histology is very similar to the fundic region of the stomach of monogastric animals. The surface epithelium here is simple columnar, not stratified squamous. There are gastric pits (foveolae) and below those, there are gastric glands of the fundic type. The glands contain parietal cells (which make hydrochloric acid) and chief or zymogenic cells which make digestive enzymes.

Review of the four-part Ruminant Stomach Parts Rumen Reticulum Omasum abomasum

Monogastric (non-ruminant) One or simple stomach structure mostly carnivores and omnivores

Monogastric Animal Digestive Tract Mouth Stomach Small Intestine Large Intestine or Colon