Digestion

  1. 6 processes of the digestive system
    • ingestion 
    • secretion - (enzymes, acids, water, etc) 
    • mixing and propulsion - contract and relax to turn food into nutrient molecules
    • digestion 
    • absorption 
    • elimination/defecation
  2. types of digestion
    • mechanical - teeth grind food, enzymes disolving molecules 
    • chemical - splitting of large (carb, lipid, protein, nucleic acid)
  3. divisions of digestive system
    • the alimentary canal (digestive tract) 
    • accessory digestive organs
  4. histology of alimentary canal
    • mucosa - inner lining og GI tract, secrete hormones, mucus, absorbs end products, protects against infection 
    • submucosa - contains lymphoid molecules, potect aginst disease, blood vessels, and elastic tissue
    • muscularis - contains smooth and skeletal muscle (segmentation and peristalsis)
    • serosa - not found in esphagus
  5. 5 major peritoneal folds and ligaments
    • greater omentum - largest peritoneal fold. also has a lot of adipose tissue, lympth nodes 
    • falciform ligament - attaches to liver and anterior abdominal wall and diaphragm
    • lesser omentum - pathway for blood vessels entering the liver, and contains the hepatic portal, artery, bile duct, and lymph nodes
    • mesentery - a fan shaped fold of the peritoneum, loaded with fat
    • mesocolon - two seperate folds of the peritoneum, carries blood to lympathic vessels to the intestines
  6. bolus
    food ground into bolus (in mouth)
  7. what begins chemical breakdown of food
    salivary gland
  8. types of salivary glands
    • submandibular glands (found underneath the mandible)
    • sublingual glands (underneath the tongue)
    • parotid glands (between ear and masseter and skin)
  9. enamel
    hardest surface in the body
  10. deglutition
    swallowing
  11. esophogeal glands produce
    mucus, to lubricate bolus and reduce friction

    ** peristalsis begins in the esophagus
  12. esophageal process
    • peristalsis
    • esophagus does not produce digestive enzymes 
    • oesophagus does not carry the absorption
  13. chyme
    bolus + gastric gland secretion
  14. protein digestion
    begins in the stomach
  15. goblet cells
    secret mucus
  16. parietal cells
    secrete hydrochloric acid (pepsinogen to pepsin) and intrinsic factor (absorption of B12)
  17. chief cells
    secrete pepsinogen and secrete gastric lipase
  18. enteroendocrine cells
    release hormones (histamine, serotonin, gastrin, endorphins, somatostatin)
  19. gastric phase
    • stomach distension activates stretch receptors
    • food chemicals activate chemoreceptors which activate G cells which secrete gastrin
  20. 90% of digestion and absorption
    occurs in small intestines (duodenum, jujunum, ileum, plicae circulares)
  21. villa
    increase surface area for absorption and digestion
  22. microvilli
    also increase surface area
  23. functions of the pancreas
    • islets of Langerhans release insulin and glucagon, remaining 1% of clusters form the endocrine 
    • pancreatic exocrine cells secrete pancreatic juice
  24. functions of large intestines
    • reabsorption of water/electrolytes
    • production and absorption of vitamin B and K 
    • elimination of feces
  25. goblet cells produces
    mucus for lubrication of feces
  26. IBS
    affects large intestines
  27. peritonitis
    inflamed infected pouches ruptures, spilling intestinal contents into abdominal cavity
  28. crohns disease
    mostly affects ileum and the cecum
Author
misol
ID
350394
Card Set
Digestion
Description
PCOM Digestion AP 4
Updated