What is the difference between monogastric and polygastric animal in terms of structure and function?

Answer 1

The main difference between monogastric and polygastric digestion is polygastric contains multiple stomachs, whereas, the monogastric is only one stomach. Further differences include, ruminant animals produce CO2 and methane gases, plolygastric animals can bloat, whereas monogastric animals do not.

Polygastric or ruminant animals have one stomach with four compartments, ruminant animals will eat as much as they can then at the resting period will regurgitate the undigested feedstuffs further filling the remaining three compartments. Poly gastric animals do not have a sphincter valve, allowing the undigested feedstuffs to re enter the mouth for further chewing. Each stomach aids in a different digestive function, the rumen mixes and stores feedstuff, this stomach contains protozoa that synthesizes protein and vitamins. Rumen also breaks down fibrous feeds into volatile fatty acids (VFA's uncluding Acetic, Butryic, and Propionic acids), cellulose and hemo-cellulose, protein and non structural carbohydrate (pectin, sugars, and starches). The reticulum catches any hardware or metal that is swallowed by the animal, there are no enzymes secreted. The Omasum does not have a major affect on digestive activity, it's main function is to communicate with the rumen and aid in mixture, it also reduces the particle size of the feed by causing a grinding action. The Abomasum, known as the true stomach secretes enzymes from the inner wall.

Monogastric stomach regulates the movement of food into the intestines and begins the digestion of specific nutrients. The stomach contains two sphincters that aid in the movement of feedstuffs, the cardiac sphincter, located at the top of the stomach. This sphincter stops food from re-entering the esophagus and mouth. The second sphincter is located at the bottom of the stomach called the Pyloric sphincter, this stops food and vial from entering back into the stomach cavity. The stomach is composed of three layers of muscles, when these muscles contract gastric contents are churned and mixed.