UNIT5 YIPPEE

  1. Alimentary Canal: aka gastrointestinal tract; tubular part of the digestive tract from the mouth to the anus; includes the mouth, pharynx, esophagus, stomach, small intestine, and large intestine

  2. Bolus: food is chewed and mixed with saliva. Then, the tongue rolls this mixture into a mass.

  3. Duodenum: where most of the chemical digestion occurs; receives chyme, gastric juices, enzymes from the pancreas, and bile from the gallbladder and liver to accomplish its role

  4. Feces: non-digested food, aka waste/stool

  5. Iluem: where important vitamins like vitamins A, B12, E, D, and K are absorbed; has the ileocecal valve at the end that connects to the large intestine

  6. Ingestion: eating; occurs only in the mouth

  7. Intestinal villi: maximize surface area for nutrient absorption into the blood 

  8. Jejunum: where most of the nutrient absorption into the blood takes place

  9. Lumen: passageway; allows for the passage of digested food; the opening inside a tubular body structure that is lined by body tissue known as an epithelial membrane

  10. Mesentery: a sheet of two serous membranes fused back to back that provides routes for blood vessels, nerves, and lymphatic vessels to the small intestines. This structure also holds the organs in place and stores fat

  11. Mucosa: Innermost layer of the alimentary canal.

  12. Muscularis: Smooth muscle layers of the alimentary canal; middle layer of smooth muscle; critical for peristalsis

  13. Peristalsis: Rhythmic waves of muscular contraction in the walls of certain tubular organs.

  14. Propulsion: Movement of food through the GI tract; peristalsis

  15. Pyloric sphincter: located at bottom of the stomach; gatekeeper, controls when chyme can enter the duodenum

  16. Serosa: Outer covering of the alimentary canal; houses the nerves, blood vessels, and lymphatic vessels for each structure

  17. Submuscosa: Layer of the alimentary canal beneath the mucosa; middle layer of loose areolar connective tissue; provides tube with elasticity

  18. Function of Digestive System: Convert the food we eat into the energy and raw materials that build and fuel our bodies

  19. Accessory (support) structures: teeth, tongue, salivary glands, gallbladder, liver, and pancreas; food does not pass through these structures, but they are needed for digestion

  20. Chemical digestion: secreted enzymes chemically break down food molecules into their simplest form (monomers) so that they can be absorbed into the blood, transported, and used by our cells

  21. Absorption: the transport of the end result of our digested food through the walls of the GI tract and into the blood (or lymph) to be transported

  22. Defecation: elimination of indigestible substances through the anus as feces; occurs only in the large intestine; absorption of nutrients is over, but H2O absorption continues

  23. Stratified squamous epithelial cells: in the mouth, esophagus, and anus to protect against abrasive foods

  24. Simple columnar epithelial cells: in the stomach and intestines for absorption and secretion

  25. Where is Amylase found?: in saliva

  26. What does amylase digest?: starches

  27. What product is formed due to amylase?: maltose; a disaccharide

  28. Where are Pepsin and HCl found?: in gastric juice

  29. What do Pepsin and HCl digest?: proteins

  30. What product is formed due to Pepsin and HCl?: partially digested proteins

  31. Where are proteases, lipases, and amylases found?: in pancreatic juice

  32. What do proteases, lipases, and amylases digest?: proteins, fats (in bile), and starches

  33. What product is formed due to proteases, lipases, and amylases?: peptides and amino acids, fatty acids, glycerol, maltose

  34. Where are peptidases, sucrase, lactase, and maltase found?: intestinal enzymes

  35. What do peptidases, sucrase, lactase, and maltase found digest?: peptides, sucrose, lactose, and maltose

  36. What product is formed due to peptidases, sucrase, lactase, and maltase?: amino acides, glucose, fructose, and galactose

  37. Where are bile salts found?: in liver bile

  38. What do bile salts digest?: fats

  39. What product is formed due to bile salts?: fat droplets

  40. Enteric nervous system: the in-house nerve supply just for the aGi tract for regulating the activities of the digestive system (part of the autonomic nervous system)

  41. Vagus nerve: The enteric nervous system communicates with the CNS via the…

  42. Gastrin: produced by G cells

  43. Serotonin and Histamine: increase/activate the release of HCl and stimulate muscle contractions in the stomach and intestines

  44. Gastric fluid secretion phase 1 - Cephalic Phase: “reflex” phase in the brain; before food even enters the stomach, external stimuli trigger parasympathetic fibers in vthe agus nerve to prep the stomach for incoming food

  45. Gastric fluid secretion phase 2 - Gastric Phase: in the stomach; mechanical and chemical stimuli increase the release of more gastric fluid, gastrin, and HCl secretion

  46. Gastric fluid secretion phase 3 - Intestinal Phase: in the intestines; receptors in the duodenum receive chyme, intestinal cells secrete more gastrin