Digestive System of Mammals

Biology

Mammals

Grazing Herbivore: Herbivores digestive systems can consist of one of two types of insides, it can be a foregut fermenter where the Foregut Fermeters has two parts (a tubiform and a sacciform fore stomach) containing lots of microbes. The stomach is bigger than that of a hindgut fermenter considering its usually a bigger animal, the stomach has an extra chamber to help devour glucose from the cellulose (the herbivores diet is largely cellulose and is broken down by the microbes) and nutrients and then produce fatty acids that the animal can use for energy, It also usually has a long small intestine (and usually has small expansions along the intestines to accomodate for so much bacteria), with a a caecum thats not to long and a medium length colon (Microbes can be digested further along the digestive tract and they're are also a source of protein) Forgut fermenters are usually larger herbivores and forgut fermentation is a slower digestive process. As opposed to,

Hindgut fermenters that use bacteria only and fermentation in their hindgut, has the small intestine that is shorter than a foregut fermenters small intestine, the caecum which is usually big and expanded for microbial fermentation and proximal colon which is very long, longer than that of a foregut fermenter. Microbes that are cleaned out cannot be digested properly and protein is lost. Hindgut fermenters are usually the smaller mammals.

Even thought its not part of the digestive system teeth are very resourceful for aiding digestion, in all Herbivores they have a Horny pad which helps initially crush the food and a meeseter that is larger than that of a carnivore so it can chew for longer, they have cainines at the front and molars and pre molars that grind at the back, so that the foodis crushed and soft making the break down and digestion of food easier.

Example: Cow chews its food for a long time to crush it andmake it easier to digest, then the food moves down the oesophagus to the Rumen (the first partof the stomach where the fermentation occurs, then the next stage it moves to the honeycomb like chamber called the Reticulum (which prepares food for regurtitation), then it regurgitates it back up and starts again, once its been through this stage enough the third part is the omasum, then finally moves onto the abomasum (rennet stomach).

Carnivore: Carnivores have very different digestive systems because of the different diet, carnivores eat predominantly meat, so therefore there is more protein and less cellulose, so the digestion will occur in the stomach and further more finish in the duodenum, (part of the small intestine just under the stomach) so the insides need to have different purposes for the digestion,absorbtion of nutrients occurs largelyin small intestine. They have an average sized stomache in relation to their size, alot of the digestion occurs in the stomach, they have a very short colon and a short and wide small intestine, and their caecum and appendix is poorly developed and for all intensive purposes are not aknowledged. To aid digestion prior to entering the stomach (even though its not part of the digestive system) their teeth, they have long sharp canines for trapping and locking prey in their mouth, and for stabbing, then theres the premolars for cutting and molars for grinding and the carnissals to cut and break.

Example: A Tasmanian devil will eat its prey which is swallowed and follows down the oesophagus to the stomach then follows the small intestine to the caecum, then lastly passes through the large intestine,to the anus.

Nectar feeding animal: Nectar feeders eat the nectar from plants so therefore they dont have use for teeth, they have a long papillae (hair like tounge) to pick up the nectar. They have a very small stomach because of the nectar only diet, (Nectar being mostly made up of sugar) they dont need to do alot of digestion so stomach isnt put to alot of use, and their intestines arent very long mainly used for degestion of pollen.

Example: Honey Possum has a much simpiler digestive system,it only consists of the stomach, intestine then the anus.

Vertebrate Herbivore is an animal with a backbone that eats plant matter, it would have a digestive system that consists of a long small intestine, a well developed large caecum, and a long colon, with two types of digestion, depending on the different herbivores hindgut and foregut digestion. The long small intestine is so, because it contains a lot of cellulose and fiber makes up their diet these components are difficult to digest, so therefore herbivores need longer digestive systems to cope with the nutrients. The well developed large caecum is so that the cellulose from the plants can be stored and fermented. The long colon in herbivorous animals, tends to be a highly advanced organ involved in water and electrolyte absorption, vitamin absorbtion and production, and fermentation of fibrous plant materials. The colons of herbivores are usually wider than their small intestine.

Vertebrate Carnivore is an animal with a backbone that eats mostly meat, its digestive system would be made up of large stomach, a small non exsistant caecum and appendix and the small intestine, and large intestine. A carnivore's saliva does not contain digestive enzymes. Carnivores have a simple (single-chambered) stomach as opposed to Herbivores which can have 4 chambers for example cows. Since most carnivores average a kill only about once a week, a large stomach volume is a plus because it allows them to fill up when eating, taking in as much meat as possible at once which can then be put off to be digested at a later time. A carnivore's stomach also secretes powerful digestive enzymes with about 10 times the amount of hydrochloric acid than a human or herbivore. A carnivore's small intestine is a tool designed for rapid elimination of food that rots quickly. A carnivore's large intestine is relatively short. This passage is also relatively smooth and runs fairly straight so that fatty wastes high in cholesterol can be easily eliminated out before they start to putrefy. The large stomach is useful and big because their diet is mostly protein so most of the digestion will occur in the stomach, and it needs to be large enough. The small non existent caecum and appendix are because those are only used in Herbivores because the meat (protein) in the carnivores diet doesnt need to be fermented like the herbivores they dont require use of the caecum. The large intestine (colon) of carnivores is simple and very short, as its only purposes are to absorb salt and water.