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Digestion PowerPoint Presentation

Digestion

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Digestion

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  1. Digestion Do it or DIE

  2. Digestion • Digestion is the process of breaking down feed into simple substances that can be absorbed by the body. • Absorption is taking the digested parts of the feed into the bloodstream • The digestive system consists of the parts of the body involved in chewing and digesting feed • This system also moves the digested feed through the animal’s body and absorbs the products of digestion

  3. Four Types of DigestiveSystems • Monogastric (simple) • Avian • Ruminants (polygastric) • Pseudo-ruminants

  4. Monogastric Digestive System • A monogastric digestive system has a simple stomach.

  5. The Stomach • The stomach is a muscular organ that stores ingested feed and moves it into the small intestine • The stomach secretes acid • Stomach has a low pH of 1.5 – 2.5 • Destroys most bacteria • Breaks down feed materials

  6. Monogastric Animal Feeds • The best types of feeds for monogastric animals are concentrated feeds • Grains rather than large amounts of roughage

  7. Types of Monogastric Animals • Dogs • Cats • Swine • Humans

  8. Avian Digestive System • Poultry digestive tract

  9. Avian Digestion • No Teeth = No Chewing • The feed is emptied from the mouth directly into the Crop • The crop is where the food is stored and soaked • Feed leaves the crop, passes through the proventriculus, which is similar to a normal stomach, and into the gizzard • The gizzard is a very muscular organ, which contains stones or grit • The gizzard is a bird’s teeth

  10. Polygastric or Ruminant Digestive System • Large stomach divided into compartments • Designed for food to be ingested, eructated, chewed, and swallowed again

  11. Polygastric Structure • The largest section of the stomach is the Rumen • Contains bacteria and other microbes to cause fermentation • The reticulum is the section of the stomach that causes eructation or “Belching” • Also known as the “Hardware Stomach” because it collects foreign objects such as stones or nails • The third section is the Omasum • Filters substances and removes water • The last section is the Abomasum • Secretes gastric juices • Similar to the true stomach in a monogastric animal

  12. Pseudo-ruminant • Animals that eat large amounts of roughage, but do not have several compartments in the stomach are pseudo-ruminant animals

  13. Pseudo-ruminant • Digestive system does some of the same functions as those of ruminants • Able to digest large amounts of roughage because of a greatly enlarged cecum and large intestine • Examples of pseudo-ruminants are horses, rabbits, guinea pigs, and hamsters

  14. Basic Structure of the Digestive System • The mouth • Contains teeth, except birds, a tongue, and salivary glands • Teeth • Grind feeds in a process called mastication • Ruminants only have bottom teeth and a hard dental plate at the top • All have molars on top and bottom • Tongue • Contains taste buds to help determine which feeds are edible • Aids in moving feeds around to the teeth and esophagus • Salivary glands • Are activated when an animal is hungry or smells feed • Secrete a watery substance to help break down feeds into a mash • Some animals contain enzymes

  15. Basic Structure of the Digestive System • The esophagus • A hollow muscular tube leading from the mouth to the stomach • Moves feed by peristalsis

  16. Basic Structure of the Digestive System • The stomach • A muscular organ which grinds feeds, adds digestive juices, and removes some water

  17. Basic Structure of the Digestive System • The small intestine • Probably the most important digestive organ, since this is where most absorption of nutrients takes place • The first division of the small intestine is the duodenum, which is where bile and digestive juices are added • Bile is a substance secreted by the liver to help digest fat • Bile is stored in the gall bladder, where it leads to the duodenum

  18. Basic Structure of the Digestive System • The large intestine • Some absorption takes place here • Mostly water is removed • In pseudo-ruminants the large cecum holds undigested feeds for fermentation • The rectum • Prepares waste for expulsion • The anus • Final organ in the digestive system • Contains a sphincter muscle which remains closed until bowel movement