Digestive System

Bianca Otarola

June 7th, 2013

6th period

The Digestive System

        A digestive system's job is to break down food into molecules the body can use. An example would be turning carbohydrates into monosaccharides for energy. The organs within the digestive tract carry out the digestive process.  Digestion includes the mechanical and chemical breakdown of food into nutrients that are needed. There are four main types of digestive systems: monogastric, avian, ruminant, and pseudo-ruminant.

        A monogastric system has one stomach. The stomach secretes acid, with the acid being a pH of 1.5 to 2.5. The low, acidic pH destroys bacteria and breaks material down. Some examples of monogastric animals are dogs, cats, and humans. The avian digestive system is in poultry. Poultry only break their food into small, tiny pieces so that they can swallow the food. They don't have any teeth to chew with. The food enters the mouth, travels through the esophagus, and empties into where food is stored and soaked (crop). The food then moves into the bird's stomach, where acids are secreted. The food then makes its way to the gizzard, the small intestine, and then to the large intestine. Food that is not digestible travels into the cloaca. The ruminant digestive system is a large stomach that is divided into four parts - the rumen, the reticulum, the omasum, and the abomasum. The ruminant system is in cattle, sheep, goats, and deer. They mainly eat hay. They mainly just swallow their food, there's not a lot of chewing in the process. A pseudo-ruminant is an animal that eats a lot of roughage but doesn't contain a stomach with different compartments. The pseudo-ruminant digestive system does the same thing of a ruminant system, but the pseudo-ruminant can swallow big amounts of roughages because of their large intestine. They usually eat grains and wheat. Some examples are horses, rabbits, and hamsters (http://www.cusd4.org/vimages/shared/vnews/stories/4e679ba30e7a0/Types%20of%20Animal%20Digestive%20Systems.pdf).
        I actually don't think there's a big disadvantage to having a monogastric digestive system; except if an organism were to eat something that were not digestible. That would be horrible. A disadvantage of having an avian digestive system would be if the poultry weren't able to break the food into pieces. For the ruminant digestive system, if they didn't have all of the four parts that their stomach is supposed to be divided into. Their food wouldn't be digested properly. The pseudo-ruminant digestive system is actually kind of scary. What would happen if an organism ate an amount of food that was too big? The food probably wouldn't digest properly, either.