Digestive System

  1. Two groups of organs:
    • alimentary canal (gastrointinal or GI tract)
    • accessory digestive organs
  2. Alimentary canal (gastrointestinal or GI tract) includes:
    • mouth
    • pharyn
    • esophagus
    • stomach
    • small intestine
    • large intestine
  3. Alimentary canal (gastrointestinal or GI tract) does what to food?
    digest and absorbs food
  4. Accessory digestive organs include:
    • teeth
    • tongue
    • bladder
    • digestive glands
  5. Digestive glands include:
    • salivary glands
    • liver
    • pancreas
  6. 6 essential activities of digestive processes:
    • ingestion
    • propulsion
    • mechanical digestion
    • chemeical digestion
    • absorption
    • defecation
  7. Adjacent segments of alimentary tract organs alternately contract and relax, which moves food along the tract distally.
  8. Nonadjacent segments of alimentary tract organs alternately contract and relax, movign food forward then backward. Food mixing and slow food propulation occurs.
  9. Serious membrame of the abdominal cavity.
  10. Peritoneum includes:
    • visceral peritoneum: on external surface of most digestive organs
    • partietal peritoneum: lines the body wall
  11. Peritoneal cavity is found _____ the two _____. And _____ lubricates mobile _____.
    • between
    • peritoneums
    • fluid
    • organs
  12. Double layer of peritoneum.
  13. Two functions of the mesentary:
    • routes for blood vessels, lymphatics, and nerves
    • holds organs in place and stores fat
  14. Organs that lie posterior to the peritoneum.
  15. Organs that are surrounded by the peritoneum.
    intraperitoneal (peritoneal)
  16. Fout basic layers (tunics):
    • mucosa
    • submucosa
    • muscularis externa
    • serosa and/or adventitia
  17. The mucosa lines the _____.
  18. Three functions of mucosa:
    • secretes mucus, digestive enzymes and hormones
    • absorbs end products of digestion
    • protects against infectious disease
  19. Three sublayers of mucosa:
    • epithelium
    • lamina propria
    • muscularis mucosae
  20. Simple columnar epithelium and mucus-secreting cells; may secrete enzymes and hormones (e.g., in stomach and small intestine)
    epithelium mucosa
  21. Two functions of epithelium mucosa:
    • protects digestive organs from enzymes
    • eases food passage
  22. Loose areolar connective tissue.
    lamina propria mucosa
  23. Lamina propria mucosa are capillaries for _____ and _____; also lymphoid _____.
    • nourishment
    • absorption
    • follicles
  24. Smooth muscle that produces local movements of mucosa.
    muscularis mucosae
  25. Dense connective tissue. Includes: blood and lymphatic vessels, lymphoid follicles, and submuscosal nerve plexus
  26. Responsible for segmentation and peristalsis. Includes inner circular and outer longitudinal layers, myenteric nerve plexus and sphincters in some regions.
    muscularis externa
  27. Replaces by the fibrous adventitia in the esophagus. Retropertitoneal organs have both an adventitia and serosa.
    visceral peritoneum
  28. Bounded by lips, cheeks, palate, and tongue. Oral orifice is the anterior opening. Lined with stratified squamous epithelium.
    oral (buccal) cavity
  29. Contains orbicularis oris, and buccinator muscles, vestibule, labial frenulum and oral cavity proper lies within the teeth and gums.
    lips and cheeks
  30. Recess internal to lips and cheeks, external to teeth and gums.
  31. Median attachment of each lip to the gum.
    labial frenulum
  32. Two types of palates:
    • hard palate
    • soft palate
  33. Palatine boes and palatine procces of the maxillae; slightly corrugated to help create friction against the tongue.
    hard palate
  34. Fold formed mostly of skeletal muscle; closes off the nasopharynx during swallowing and uvula projects downward from its free edge
    soft palate
  35. Three functions of the tongue:
    • repositioning and mixing food during chewing
    • formation of the bolus
    • initiation of swallong, speech, and taste
  36. Part of tongue that attaches to the floor of the mouth.
    lingual frenulum
  37. Three types of salivary glands:
    • extrinsic
    • intrinsic (buccal)
    • secretion (saliva)
  38. Glands found in parotid, submandibular, and sublingual.
    extrinsic salivary glands
  39. Glands that are scattered in the oral mucosa.
    intrinsic (buccal) glands
  40. Four fucntions of secretion (saliva):
    • cleanses the mouth
    • moistens and dissolves food chemicals
    • aids in bolus formation
    • contains enzymes that begin the breakdown of starch
  41. Primary and permanent dentitions are formed by age ___.
  42. Two sets of teeth:
    • deciduous
    • permanent
  43. Erupts at 6-24 months of age (20 of them); and roots are resorbed, teeth fall out at 6-12 years as permanent teeth develop.
    deciduous teeth
  44. All except third molars erupt by the end of adolescence (32 of them)
  45. Chisel shpaed for cutting.
  46. Fanglike teeth that tear or pierce.
  47. Have broad crowns with rounded cusps for grinding or crushing
    • premolars (bicuspids)
    • molars
  48. The exposed part above the gingiva (gum).
  49. The crown is covered by _____ which is the hardest substance in the body (calcium salts and hydroxyapatite crystals)
  50. Portion embedded in the jawbone; connected to crown and neck.
  51. Calcified connective tissue; covers root and attaches it to the periodontal.
  52. Forms fibrious joint called a gomphosis.
    periodontal ligament
  53. Groove where gingiva borders the tooth.
    gingival sulcus
  54. Bonelike material under enamel; maintained by odontoblasts of pulp cavity.
  55. Cavity surrounded by dentin.
    pulp cavity
  56. Connective tissue, blood vessels, and nerves.
  57. Extends from pulp cavity to the apical foramen of the root.
    root canal
  58. Allows passage of food, fluids, and air; stratified squamous epithelium lining; made up skeletal muscle layers.
    oropharynx and laryngopharynx
  59. Inner longitudinal, outer pharyngeal constrictors.
    skeletal muscle layers of pharynx
  60. Flat muscular tube from laryngopharynx to the diaphragm to the gastroesophageal sphincter in the superior aspect of the stomach; approximately 25cm long; has adventitia instead of serosa.
    esophagus (gullet)
  61. Four digestive processes of the mouth:
    • ingestion
    • mechanical digsestion
    • chemical digestion
    • propulsion
  62. Mastication is partly voluntary, partly reflexive.
    mechanical digestion
  63. Contains salivary amylase and lingual lipase.
    chemical digestion
  64. Deglutition (swallowing).
  65. The parts of the stomach's gross anatomy:
    • cardiac region (cardia)
    • fundus
    • body
    • pyloric region
    • lesser/greater curvation
    • leser/greater omentum
  66. Surrounds the cardiac orifice.
    cardiac region
  67. Dome-shaped region beneath the diaphragm.
  68. Midportion of stomach.
  69. Antrum, pyloric canal, and pylorus; pylorus is continuous with the duodenum thorugh the pyloric valve (sphincter).
    pyloric region
  70. Convex lateral surface.
    greater curvature
  71. Concave medial surface.
    lesser curvature
  72. From the liver to the lesser curvature.
    greater omentum
  73. Drapes from greater curvature; anterior to the small intestine
    greater omentum
  74. Three factors of stomach anatomy:
    • four tunics
    • muscularis and mucosa are modified
    • mucosa
  75. Three layers of smooth muscle; inner oblique layer allows stomach to churn, mix, move, and physically break down food.
    muscularis externa
  76. Simple columnar epithelium composed of mucous cells; layer of mucus traps bicarbonate-rich fluid beneath it; gastric pits lead into gastric glands
  77. Four cell types of gastric glands:
    • mucous neck cells (secrete thin, acidic mucus
    • parietal cells - HCL
    • chief cells - pepsinogen
    • enteroendocrine cells
  78. Major organ of digestion and absorption; 2-4m long; from pyloric sphincter to ileocecal valve; has subdivision.
    small intestine
  79. Subdivision of small intestines:
    • duedenum (retroperitoneal)
    • jejunum (attached posteriorly by mesentery)
    • ileum (attached posteriorly by mesentery)
  80. The bile duct and main pancreatic duct. Joined at the hepatopancreatic ampulla, enters the duodenum at the major duodenal papilla and are controlled by the hepatopancreatic sphincter.
  81. What three factors increases surface area of proximal part for nutrient absorption?
    • circular folds (plicae circulares)
    • villi
    • microvilli
  82. Motile fingerlike extension (~1mm high) of the mucosa. Includes villus epithelium; simple columnar absorptive cells (enterocytes) and globelet cells.
  83. Projections (brush border) of absorptive cells; bear brush border enzymes.
  84. Secretory cells that produce intestinal juice; enteroendocrine cells; intraepithelial lymphocytes (IELs); paneth cells; stem cells
    intestinal crypt epithelium
  85. Release cytokines that kill infected cells
    intraepithelial lymphocytes (IELs)
  86. Secretes antimicrobial agents (defensis and lysozyme).
    paneth cells
  87. Peyer's patches protect distal part against bacteria; duodenal (Brunner's) glands of the duodenum secrete alkaline mucus.
  88. Largest gland in the body; four lobes - right, left, caudate,a nd quadrate.
  89. Separates the (larger) right and (smaller) left lobes; suspends liver from the diaphragm and anterior abdominal wall.
    falciform ligament of liver
  90. Remnant of fetal umbilical vein along free edge of falciform ligament.
    round ligament (ligamentum teres) of liver
  91. Three types of ssociated structures of liver:
    • lesser omentum anchors liver to stomach
    • hepatic artery and vein at the porta hepatis
    • bile ducts
  92. Common hepatic duct leaves the liver; cystic duct connects to gallbladder; formed by the union of the above two ducts.
    bile ducts
  93. Two factors of liver lobules:
    • hexagonal structural and functional units
    • longitudinal central vein
  94. Filter and process nutrient-rich blood; composed of plates of hepatocytes (liver cells).
    hexagonal structural and functional units of liver lobules
  95. Bile duct receives bile from bile canaliculi; portal arteriole is a branch of the hepatic artery; hepatic venule is a branch of the hepatic portal vein.
    portal triad at each corner of lobule
  96. Leaky capillaries between hepatic plates
    liver sinusoids
  97. (hepatic macrophages) in liver sinusoids.
    Kupffer cells
  98. Four functions of hepatocytes:
    • process bloodborne nutrients
    • store fat-soluble vitamins
    • perform detoxification
    • produce ~900ml bile per day
  99. Yellow-gree, alkaline solution containing bile salts, bilirubin, cholesterol, neutral fats, phopholipids and electrolytes.
  100. Cholesterol derivatives that function in fat emulsification and absorption.
    bile salts
  101. Pigment formed from heme.
  102. Thin-walled muscular sac on the ventral surface of liver; stores and concentrates bile by absorbing its water ions; releases bile via the cystic duct, which flows into the bile duct.
Card Set
Digestive System
Digestive System