A & P

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A & P
2010-11-21 21:06:13

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  1. What are the two groups of organs of the digestive tract?
    • Alimentary canal (gastrointestinal tract)
    • Accessory digestive organs
  2. The organs of the alimentary canal include
    Mouth, pharynx, esophagus, stomach, small intestine and large intestine
  3. What are the accessory organs of the digestive system?
    What are the diestive glands?
    • Teeth, tongue and gallbladder
    • Salivary, liver and pancreas
  4. What are the six essential activites of the digestive system?
    • Ingestion
    • Propulsion
    • Mechanical digestion
    • Chemical digestion
    • Absorption
    • Defecation
  5. Adjacent segments of alimentary tract alternately contract and relax, which moves food along the tract distally describes
  6. What are the 4 things saliva does?
    • Cleanses the mouth
    • Moistens and dissolves food chemicals
    • Aids in bolus formation
    • Contains enzymes that begin the breakdown of starch
  7. Saliva is secreted by
    serous and mucous cells
  8. Saliva contains
    • electrolytes
    • Enzymes (that break down starch)
    • mucin
    • Metabolic wastes (urea and uric acid)
    • Lysozome, lgA, defensins, and a cyanide compound protect against microorganisms
  9. _______________ (_______, _______) ______________ keep the mouth moist
    Intrinsic (small, scattered) glands
  10. _______________________ (__________, ________________) produce secretions when ingested food stimulates chemoreceptors and mechanoreceptors in the mouth
    Extrinsic salivary glands (Large, outside of oral cavity)
  11. What digestive processes happen in the mouth?
    • Ingestion
    • Mechanical digestion
    • Chemical digestion
    • Propulsion (deglutition)
  12. Deglutition involves
    the tongue, soft palate, pharynx, esophagus, and 22 mucle groups
  13. What is the buccal phase?
    Voluntary contraction of the tongue
  14. The pharyngeal-esophageal phase is ________. It is part of what digestive process?
    • Involuntary
    • Deglutition
  15. What is the stomach's job
    Digest proteins
  16. The ____________ of the stomach allows it to churn, mix, move and physically break down food
    inner oblique layer
  17. Mucosa layer of the stomach is made of
    simple columnar epithelium composed of mucous cells
  18. What types of cells are in gastric glands?
    • Mucous neck cell (secrete thin, acidic mucus)
    • Parietal cells
    • Chief cells
    • Enteroendocrine
  19. Glands in the fundis and body produce ____________
    most of the gastric juice
  20. Parietal cells secrete (2)
    • HCI (pH denatures protein in food, activates pepsin and kills bacteria)
    • Intrinsic factor (glycoprotein required for absorption of vit B12 in small instestine)
  21. Chief cells secrete
    • Inactive enzyme pepsinogen
    • Activated to pepsin by HCI and by pepsin itself (a positive feedback mechanism)
  22. Enteroendocrine cells secrete _________ into the lamina propria
    chemical messengers
  23. What are the chemical messengers secreted into the lamina propria?
    • Paracrines (local hormones)
    • Hormones
  24. Which paracrines are secreted by the gastric glands?
    • Serotonine (stomach contraction)
    • histamine (activates release of HCI)
  25. What hormones are secreted by gastric glands?
    Somatostatin (inhibits gastric) and gastrin (stimulates gastric)
  26. What are the 3 things that protect the lining of the stomach?
    • Layer of bicarbonate-rich mucus
    • Tight junctions between epithelial cells
    • Damaged epithelial cells are quickly replaced by division of stem cells
  27. Errosion of the stomach wall leads to
    peptic or gastric ulcers
  28. Gastritis is
    inflammation caused by anything that breaches the mucosal barrier
  29. Most peptic and gastric ulcers are caused by
    Helicobacter pylori bacteria
  30. What digestive processes occur in the stomach?
    • Physical digestion (churning)
    • Denaturation of proteins (acid)
    • Enzymatic digestion of proteins by pepsin
    • Delivers chyme to the small intestine
  31. The stomach secretes ___________required for absorption of vitamin B12
    intrinsic factor
  32. A lack of intrinsic factor leads to
    percutanious anemia
  33. Gastric secretions are regulated by
    neural and hormonal mechanisms
  34. What are the stimulatory and inhibitory phases that occur in the stomach?
    • Cephalic (reflex) phase: few minutes prior to food entry
    • Gastric phase: 3-4 hours after food enters the stomach
    • Intestinal phase: brief stimulatory effect as partially digested food enters the duodenum, folowed by inhibitory effects
  35. What are the 3 chemicals that stimulate parietal cells through second-messenger systems in the stomach?
    ACh, histamine and gastrin
  36. _______, ____________ and ________ are necessary for maximum HCI secretion
    ACh, histamine and gastrin
  37. ____________ block H2 receptors and decrease HCI release
  38. what is the stomach's response to filling? What cooderinates this?
    • Reflex-mediated receptive relaxation
    • Coordinated by the swallowing center of the brain stem. Gastric accomodation by the placticity of smooth muscle
  39. __________________ move toward the pylorus at the rate of 3 per minute
    peristaltic waves
  40. __________- and _____________ increase force of contraction in stomach
    Distension and gastrin
  41. Gastric contractile activity is most vigorus near
    the pylorus
  42. Chyme is either delivered _____________ or _____________
    • in about 3 ml spurts into the duodenum
    • forced backward into the stomach
  43. As chyme enters the duodenum receptors _____________________ and ____________________
    respond to stretch and chemical signals and enterogastric reflex and enterogastrones inhibit secretion and duodenal filling
  44. _____________ moves quickly though the duodenum. ________________ remains in the duodenum 6 hours or more
    • Carbohydrate-rich chyme
    • Fatty chyme
  45. What are the 3 jobs of the small intestine?
    • Absorb nutrients into the bloodstream
    • Allow for chemical digestion as food passes through it
    • Collects several chemicals from external organs of digestive system
  46. What are the subdivision of the small intestine?
    • Duodenum (retroperitoneal)
    • jejumum
    • ileum
  47. duodenum collects from
    stomach and external organs
  48. The jejunum finalizes
    food digestion process
  49. the ilium maximizes
    food absorption process
  50. the bile duct and main panceatic duct join ______________ enter _____________ are controlled by ______________
    • at the hepatopancreatic duct
    • the duodenum at the major duodenal papilla
    • the hepatopancreatic sphincter
  51. What are the structural modifications of the small intestine that increase the surface area of proximal part for nutrient absorption?
    • Circular folds (plicae circulares)
    • Villi
    • Microvilli
  52. Circular folds are ____________ and force ____________
    • permanent
    • chyme to slowly spiral through lumen
  53. Villi are _________________________ and are made up of ____________-
    • motile fingerlike extension of the mucosa
    • Villus epithelium
  54. Villus epithelium is made of
    Simple columnar Absorptive cells (enterocytes) and Goblet cells (make mucous)
  55. Microvilli are ___________________ and bear
    • projections (brush border) of absorptive cells
    • Brush border enzymes
  56. Submucosa of small intestine is made up of
    • Peyer's patches
    • Duodenal (Brunner's) glands
  57. Peyer's patches protect
    distal part of small intestine against bacteria
  58. Duodenal glands of the duodenum secrete
    alkaline mucus (post-stomach chyme is acidic - this neutralizes it)
  59. Intestinal juice is secreted in response to
    distension or irritation of the mucosa
  60. Intestinal juice is slightly _________ and _____________
    • alkaline (basic)
    • isontonic tithe blood plasma (even concentration of water
  61. Intestinal juice is largely _____________ but contains _____________
    • enzyme poor
    • mucus
  62. Intestinal fuild facilitates
    transport and absorption of nutrients
  63. The ____________ is the largest gland in the body
  64. What are the 3 bile ducts?
    • Common hepatic duct leaves the liver
    • Cystic ducts connects to gallbladder
    • Bile duct formed by the union of the other ducts
  65. What are the four hepatocyte functions?
    • Process bloodborne nutrients
    • Store fat-soluble vitamins
    • Perform detoxification
    • Produce about 900 ml of bile per day
  66. Bile is a yellow-green, alkaline solution containing
    • Bile salts
    • Bilirubin
    • Cholesterol
    • Neutral fats
    • phospholipids
    • electrolytes
  67. Bile salts are
    cholesterol derivitives that function in fat emulsification (makes fat droplet out of fat) and absorption
  68. Bilirubin is a pigment formed from
  69. The recycling of bile salts is called
    enterohepatic circulation
  70. What are the steps of enterohepatic circulation?
    Bile salts -> duodenum ->reabsorbed from ileum -> hepatic portal blood -> liver -> secreted into bile
  71. Bile salts are recirculated ____ or more times for one meal
  72. What is the endocrine function of the pancreas?
    Pancreatic islets secrete insulin and glucagon
  73. What the exocrine functions of the pancreas?
    • Acini (clusters of secretory cells) secrete pancreatic juice
    • Zymogen granules of secretory cells contain digestive enzymes
  74. A watery alkaline solution that neutralizes chyme describes
    pancreatic juice
  75. Pancreatic juice is made up of
    electrolytes and enzymes
  76. Bile secretion is stimulated by
    • bile salts in enterohepatic circulation
    • secretin from intestinal cells exposed to HCI and fatty chyme
  77. Gallbladder contraction is stimulated by
    • cholecystokinin (CCK)
    • Vagal stimulation
  78. Cholecystokinin comes from
    intestinal cells exposed to proteins and fat in chyme
  79. CCK also causes
    the hepatopancreatic sphincter to relax (dilate and open)
  80. CCK induces
    the secretion of enzyme-rich pancreatic juice by acini
  81. Secretin causes
    secretion of bicarbonate-rich pancreatic juice by duct cells
  82. Chyme from stomach contains
    • partially digeted carbohydrates and proteins
    • undigested fats
  83. What are the requirements for digestion and absorption in the small intestine?
    • Slow delivery of hypertonic chyme
    • Delivery of bile, enzymes, and bicarbonate from the liver and pancreas
    • Mixing
  84. How does chyme move through the small intestine?
  85. Peristalsis in the small intestine is iniciated in __________________
    the late intestinal phase
  86. What are the regions of the large intestine?
    • Cecum (pouch with attached vermiform appendix)
    • Colon
    • Rectum
    • Anal canal
  87. The rectum has three
    rectal valves that stop feces from being passed with gas
  88. What are the two types of anal sphincters and what are they made of?
    • Internal anal sphincter-smooth muscle (involuntary)
    • External anal phincter-skeletal muscle (voluntary)
  89. Bacterial flora (E Coli) colonize the ________, ferment ______________, release _______________ and synthesize ________________
    • colon
    • indigestible carbohydrates
    • irritating acids and gases
    • B complex vitamins and vitamin K (blood clotting)
  90. what are the functions of the large intestine?
    • Reclaims vitamins, water, and electrolytes
    • Major function is propulsion of feces toward the anus
  91. How does the large intestine move stuff?
    Haustral contractions: Slow segmenting movements - haustra sequentially contract in response to distension
  92. _____________ is initiated by presence of food in the stomach
    Gastrocolic reflex
  93. The gastrocolic reflex activates
    three to four slow powerful peristaltic waves per day in the colon (mass movements)
  94. Parasympathetic signals stimulate _______________________ and relax the ________________
    • contraction of the sigmoid colon
    • internal anal sphincter
  95. Distension initiates
    spinal defecation reflex
  96. What are the three processes of chemical digestion?
    • Catabolic (breaking down)
    • Enzymatic
    • Hydrolysis