Alimentary Canal

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Alimentary CanalThe pathway for food

• Mouth- food is physically broken down by the
  teeth and tongue. It is chemically broken down by
  enzymes produced by salivary glands.
• Carbohydrates are changed from starch to sugar in
  the mouth by amylase.

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• 3 salivary glands
• Parotid (near the ear) is the largest.
• Sublingual (under the tongue)
• Submandibular (below the jaw)

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• 2. Pharynx- Both air and food passes through. The
  epiglottis prevents food/liquids from getting
  into the airway.
• 3. Esophagus- peristalsis (involuntary muscle
  contractions that push the food down).

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• 4. Stomach (2-4 hours)- cardiac sphincter,
  fundus, body, pyloric sphincter.
• Enzymes
• Pepsin (breaks down protein)
• Rennin (breaks down milk)
• Lipase (emulsifies fats)
• HCl (germicide and breaks down fats)

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• 5. Small intestine ( 6 meters in length). Food
  stays here for approx. 3-5 hours.
• Three sections
• Duodenum mixing bowl 25 cm in length. Point
  where digestive juices from liver and pancreas
  enters the intestines.
• Jejunum (2.5 m)- most of chemical digestion
  occurs here.

3. Ileum (3.5 m)- contains villi which absorbs
broken down food and enters the bloodstream.
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• 6. Large intestine- absorption of water and holds
  feces.
• Four sections of the large intestine
• Ascending (going up)
• Transverse (across)
• Descending (going down)
• Sigmoid (s-shaped)

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• 7. Rectum- holding area for feces. Takes about 24
  hours for food to reach this point.
• 8. Anus- most powerful sphincter in the body (and
  arent we glad!)