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ch 24 - bio169
digestive system
Question | Answer |
---|---|
Ingestion | occurs when materials enter the digestive tract via the mouth. |
Mechanical Processing | crushing and shearing that makes materials easier to propel along the digestive tract |
Digestion | the chemical breakdown of food into small organic fragments suitable for absorption by the digestive epithelium. |
Secretion | the release of water, acids, enzymes, buffers, and salts by the epithelium of the digestive tract and by glandular organs. |
Absorption | the movement of organic substrates, electrolytes, vitamins, and water across the digestive epithelium and into the interstitial fluid of the digestive tract. |
Excretion | the removal of waste products from body fluids. |
The lining of the digestive tract plays a protective role by safeguarding surrounding tissues against: | 1. The corrosive effects of digestive acids and enzymes 2. Mechanical stresses, such as abrasion 3. Bacteria that either are swallowed with food or reside in digestive tract. |
Visceral Peritoneum | covers organs within the peritoneal cavity |
Parietal Peritoneum | lines the inner surfaces of the body wall |
Mesentery | double sheets of peritoneal membrane |
Lesser omentum | stabilizes the position of the stomach and provides an access route for blood vessels and other structures entering or leaving the liver |
Falciform Ligament | helps stabilize the position of the liver relative to the diaphragm and abdominal wall |
The major layers of the digestive tract: | 1. Mucosa 2. Submucosa 3. Muscularis externa 4. Serosa |
Mucosa | Inner lining of the digestive tract |
Enteroendocrine Cells | secretes hormones that coordinate the activities of the digestive tract and the accessory glands. |