The Digestive System in Mammals

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Anatomy and Physiology of Animals/The Gut and Digestion
When glucose levels are low the liver can convert the glycogen back into glucose. The final compartment is called the abomasum. Actions for selected content:. Other specializations in the stomach are apparent in mammals with other types of diets. They must then be broken down into smaller ones by digestive enzymes - digestion , before they can be taken from the gut into the blood stream - absorption. In most animals it is large and easily seen but in rodents and rabbits it lies within the membrane linking the loops of the intestine the mesentery and is quite difficult to find. By using this service, you agree that you will only keep articles for personal use, and will not openly distribute them via Dropbox, Google Drive or other file sharing services Please confirm that you accept the terms of use.

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Do you really want to delete this prezi? Neither you, nor the coeditors you shared it with will be able to recover it again. Comments 0 Please log in to add your comment. Transcript of Mammal Digestive System The honey possum Tarsipes rostratus , is a native australian marsupial nectar feeder. The honey possum is found mainly in the southwest woodlands of Western Australia Dingo The dingo Canis Lupis Dingo is a free-ranging dog found mainly in Australia.

They live in deserts, grasslands and forest edges. Red Kangaroo The red kangaroo Macropus rufus is the largest native terrestrial mammal in Australia. It is found across mainland Australia, favouring less fertile areas of land Honey Possum Red Kangaroo A grazing herbivore, kangaroos rely solely on plants and vegetation.

They do not need to intake much water, and obtain sufficient nourishment from leaves. The digestion of microbes from vegetation in the kangaroo's stomach acts as the main source of protein. Dingo Dingos eat a diet composed of mainly meat, including animal flesh, organs and muscle tissue. This is very high in protein and fat, and provides the animal with large amounts of energy. The Honey Possum The diet is a mix of nectar and pollen, an energy rich diet needed to maintain the possum's high metabolic rate.

Nectar contains sugars including glucose, fructose and sucrose. Pollen cells contains protein, carbohydrates and fats. All of which serve as the main energy source to the organism. Common food sources include banksia pollen and nectar, bottlebrushes and dryandras. Red Kangaroo The Red Kangaroo has a specialized jaw to suit grazing habits, with increased room between the molars and the front teeth.

The stomach is long and tubular; consisting of 2 main sections, the enlarged fore-stomach and the hind stomach. The fore stomach is split into the sacciform and the tubiform by a ventral fold. The sacciform acts as a storage compartment and tubiform is mainly used for fermentation. They often regurgitate food to eat it again, which then recycles through the digestive system again.

Honey Possum The possum has a long pointed snout with a brush tip tongue that gathers pollen and nectar. The digestive system is small, as the ingested foods nectar are ready for immediate absorption when ingested. The digestive system lacks a caecum, making the small and large intestine hard to differentiate. Proteins and pollens are digested in the large intestine.

Native Australian Mammals Chemical Composition of Diet Main digestive structures and functions The Mammal Digestive System Dingo The dingo has a short and relatively non-complex digestive system due to the fact they do not digest any cellulose. The stomach is adapted to consume animal flesh. The digestive system has very poor regions for microbial fermentation; with a short small intestine.

Limited microbial digestion occurs in the shortened caecum. Similar to ruminant gut structure, the small intestine is essential in fermenting bacteria and digesting plant cellulose. The complexity of the chambered stomach allows energy to be released from microbes in the form of fatty acids; a main source of energy Red Kangaroo Honey Possum The possum's specialized nectar and pollen diet requires a 2 chambered stomach to digest the large amounts protein and energy.

The stomach serves as storage organ for the leftover nectar that's energy it not needed Dingo The simple digestive system is specific to the cellulose free diet and the lack of variation in diet.

No cell wall to break down in meat. Digestion involves mechanical and chemical activities. The mechanical part of digestion involves tearing, grinding and mixing food with enzymes.

Chemical digestion is done by various digestive enzymes. The oral cavity is responsible for the grasping and ingestion of food, grinding of food, moistening and lubrication, and formation of food boluses that are then plunged into the pharynx for swallowing. The structures of the oral cavity include lips, cheeks, teeth, tongue, palate, and salivary glands.

The evolution of the secondary palate allows for dual mastication and breathing. The hard palate separates the nasal passages from the mouth. This first appears in reptiles and further evolves into the mammalian secondary palate. During mammalian evolution, tongue became more prominent in the process of digestion. It became more mobile and muscular. In turn, the tongue could be used to manipulate food while in the oral cavity.

In addition to a means of digestion, the tongue also became the primary focus of taste receptors. Another specialization of the tongue, as seen in the cat, is the development of tongue papillae. These spiky structures are used as rasping devices when feeding, as well as grooming devices.

The specialization of teeth was a significant aspect of mammalian evolution. The teeth of a mammal are specialized to meet the needs of that animals diet. Teeth aid in tearing, cutting, and mastication of food. For instance, the cat, whose diet is mainly carnivorous possess teeth that resemble large blades with serrated edges for slicing or scissor-like cutting edges. Salivary glands are an important aspect of mammalian evolution because they produce saliva, which facilitate mastication and swallowing of food.

It provides buffered fluid in ruminants to neutralize the acidity in the rumen produced as a result of fermentation. Some animals secrete salivary amylase which converts starch into maltose. The esophagus is a muscular tube that moves boluses from the pharynx to the stomach. There are two muscle layers in the esophagus: These muscle layers, when they contract and relax, help in the movement of bolus of food by peristalsis. Peristalsis consists of relaxation followed by contraction.

In mammals, the caudal end of the esophagus is closed off by the cardiac sphincter. This structure allows for the passage of food from the esophagus to the stomach.

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