Chapter 3 Diegestion
44
Digestion, Absorption and Transport BIOL310-Nurtition
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Transcript of Chapter 3 Diegestion
Digestion, Absorptionand Transport
BIOL310-Nurtition
Digestion• Basic anatomy of the GI tract
– mouth esophagus stomach small intestine large intestine rectum anus
– lumen
GI Tract Anatomy
Digestion• Mouth
– Tongue– Teeth
•Mastication
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The Teeth
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Digestion• Pharynx
• Epiglottis
• Esophagus– Esophageal sphincters– Bolus
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Digestion• Stomach
– Chyme– Pyloric sphincter
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Digestion• Small intestine
– Duodenum– Jejunum– Ileum
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Digestion• Gallbladder
• Pancreas
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Digestion• Large intestine = colon
– Ileocecal valve– Appendix
• Rectum– Anus
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Muscular Action of Digestion
• Peristalsis
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Peristalsis & Segmentation
Muscular Action of Digestion
• Stomach action• Segmentation
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Muscular Action of Digestion
• Sphincter contractions– Reflux
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Secretions of Digestion
• Catalysts– Hydrolysis– Digestive enzymes
• Saliva– Salivary glands
•Water, salts, mucus, enzymes
Secretions of Digestion
• Stomach– Gastric juice– Gastric glands
•Water, enzymes, hydrochloric acid (HCl)
Secretions of Digestion
• Stomach– Goblet cells
•Mucus• Pancreas
– Pancreatic juice•Enzymes, bicarbonate
Secretions of Digestion
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Secretions of Digestion
• Liver– Bile
•Emulsifier
• Gallbladder
Secretions of Digestion
• Protective factors
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The Final Stage• Stools
• Colon– Fermentation of undigested
residues
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Digestion of a Sandwich
Digestion of a Sandwich
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Absorption
Absorption in theSmall Intestine
• Villi– Microvilli– Capillaries and lacteals– Chylomicrons
• Crypts
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The Small Intestinal Villi
The Small Intestinal Villi, cont’d
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Circulatory Systems• Vascular system
– Heart– Arteries– Capillaries– Veins
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Circulatory Systems• Vascular system
– Portal vein– Hepatic vein
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The Liver
Circulatory Systems• Lymphatic system
– Lymph– Thoracic duct
• Subclavian vein
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Regulation• Homeostasis• Hormones
– Gastrin– Secretin– Cholecystokinin = CCK– Gastric-inhibitory peptide =
GIP
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Digestive Problems• Choking
– Trachea– Larynx– Heimlich maneuver
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Digestive Problems• Vomiting• Diarrhea
– Irritable bowel syndrome• Constipation• Hemorrhoids• Diverticula
– Diverticulosis– Diverticulitis
Diverticula in the Colon
Digestive Problems• Belching• Gas• Hiccups• Heartburn = gastroesophageal
reflux– Antacids and acid controllers– Indigestion
Digestive Problems• Ulcers
– Peptic ulcer– Helicobactor pylorii infection– Use of certain anti-
inflammatory drugs– Disorders that cause
excessive acid secretion
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Strategies for GI Problems
Questions or Thoughts?
• If you have any questions or thoughts please feel free to post them to the discussion board or e-mail your instructor.
