Anatomy and Physiology of Animals/The Gut and Digestion

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The Digestive System in Mammals
To send content items to your Kindle, first ensure no-reply cambridge. Nutritional value and diet preference of arboreal lichens and hypogeous fungi for small mammals in the Rocky Mountains. Instead there is a horny pad against which the bottom incisors cut. The caecum is short to medium in length and the colon is medium length- as fermentation is not as important in that area. The chyme from the small intestine that enters the colon consists mainly of water and undigested material such as cellulose fibre or roughage.

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Email your librarian or administrator to recommend adding this book to your organisation's collection. However well the anatomy of the gastro-intestinal tracts of a wide range of mammals is described and quantified, there can be no real explanation of observed patterns without consideration of the mechanical and chemical properties of the food consumed, and of the digestive stages involved in its processing. This book aims to integrate findings from the many different types of investigations of mammalian digestive systems into a coherent whole.

Using the themes of food, form and function, researchers discuss models of digestive processes, linking this with evolutionary aspects of food utilisation. Macroscopic and ultrastructural studies of the gastro-intestinal tract are also presented, as are physiological, ecological and biochemical aspects of the digestion of different food types. The book ends with an integrative chapter, bringing together the themes running through the earlier sections. It is likely to be enjoyed on a first reading and used often thereafter, because of the wide range of information it presents.

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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. The small intestine does not need to facilitate bacteria fermentation as the digestive process is very fast. Complexity of digestive system specific to diet The Main chamber is around 11mm long, 2.

The secondary chamber is around half the size, connected by a small channel. 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.

Food Form and Function