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Alimentary Canal “The 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. 3 salivary glands
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Alimentary Canal“The 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.
3 salivary glands Parotid (near the ear) is the largest. Sublingual (under the tongue) Submandibular (below the jaw)
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).
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)
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.
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)
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 aren’t we glad!)