Biology 235 Human Anatomy and Physiology

Study Guide

Chapter 24
The Digestive System

Objectives

After completing this chapter, you should be able to

  1. identify the organs of the digestive system and the six basic processes they perform.
  2. describe the structures and functions of the layers that form the wall of the gastrointestinal tract.
  3. describe the nerve supply of the GI tract.
  4. describe the peritoneum and its folds.
  5. identify the locations of the salivary glands, and describe the functions of their secretions.
  6. describe the structure and functions of the tongue.
  7. identify the parts of a typical tooth, and compare deciduous and permanent dentitions.
  8. describe the location and function of the pharynx.
  9. describe the location, anatomy, histology and functions of the esophagus.
  10. describe the three phases of deglutition.
  11. describe the location, anatomy, histology and functions of the stomach.
  12. describe the location, anatomy, histology and functions of the pancreas.
  13. describe the location, anatomy, histology and functions of the liver and gallbladder.
  14. describe the location, anatomy, histology and functions of the small intestine.
  15. describe the location, anatomy, histology and functions of the large intestine.
  16. describe the three phases of digestion.
  17. describe the major hormones that regulate digestive activities.
  18. describe the disorders listed.

Keywords and Topics

Make certain that you can define, and use in context, each of the terms listed below, and that you understand the significance of each of the concepts.

  1. Identify the organs of the digestive system and the six basic processes they perform.
    1. Digestion
      1. digestive system
        1. gastrointestinal (GI) tract or alimentary canal
        2. accessory digestive organs
        3. basic processes
          1. ingestion
          2. secretion
          3. mixing and propulsion
          4. motility
          5. digestion
          6. mechanical digestion
          7. chemical digestion
          8. absorption
          9. defecation
          10. feces
  2. Describe the structures and functions of the layers that form the wall of the gastrointestinal tract.
    1. layers of the GI tract
      1. mucosa
      2. epithelium
      3. enteroendocrine cells
      4. lamina propria
      5. mucosa associated lymphatic tissue (MALT)
      6. muscularis mucosae
      7. submucosa
      8. submucosal plexus
      9. muscularis
      10. serosa
      11. visceral peritoneum
      12. adventitia
  3. Describe the nerve supply of the GI tract.
    1. neural innervation of GI tract
      1. enteric nervous system (ENS)
      2. myenteric plexus (plexus of Auerbach)
      3. submucosal plexus (plexus of Meissner)
      4. autonomic nervous system
      5. gastrointestinal reflex pathways
  4. Describe the peritoneum and its folds.
    1. peritoneum
      1. parietal peritoneum
      2. visceral peritoneum
      3. peritoneal cavity
      4. retroperitoneal
      5. greater omentum
      6. falciform ligament
      7. lesser omentum
      8. mesentery
      9. mesocolon
  5. Identify the locations of the salivary glands, and describe the functions of their secretions.
    1. mouth or oral cavity or buccal cavity
      1. cheeks
      2. lip or labium (plural is labia)
      3. labial frenulum
      4. vestibule
      5. oral cavity proper
      6. fauces
      7. hard palate
      8. soft palate
      9. uvula
      10. salivary glands
      11. parotid glands
      12. parotid duct
      13. submandibular glands
      14. submandibular duct
      15. sublingual glands
      16. lesser sublingual duct
      17. saliva
      18. salivary amylase
      19. salivation
  6. Describe the structure and functions of the tongue.
    1. tongue
    2. extrinsic muscles
    3. intrinsic muscles
    4. lingual frenulum
    5. papillae
    6. lingual glands
    7. lingual lipase
  7. Identify the parts of a typical tooth, and compare deciduous and permanent dentitions.
    1. tooth or dentis (plural is dentes)
      1. gingivae
      2. periodontal ligament (or membrane)
      3. crown
      4. root(s)
      5. neck
      6. dentin
      7. enamel
      8. cementum
      9. pulp cavity
      10. pulp
      11. root canals
      12. apical foramen
      13. dentitions
      14. deciduous teeth or primary teeth or milk teeth or baby teeth
      15. central and lateral incisors
      16. cuspids or canines
      17. first and second molars
      18. permanent teeth or secondary teeth
      19. incisors and cuspids
      20. first and second premolars or bicuspids
      21. first molars, second molars and third molars (or wisdom teeth)
      22. mechanical and chemical digestion
      23. mastication
      24. bolus
      25. salivary amylase
      26. lingual lipase
  8. Describe the location and function of the pharynx.
    1. pharynx
  9. Describe the location, anatomy, histology and functions of the esophagus.
    1. esophagus
      1. esophageal hiatus
      2. histology of the esophagus
        1. mucosa, submucosa and muscularis
        2. upper esophageal sphincter
        3. lower esophageal (cardiac) sphincter
        4. adventitia
      3. physiology of the esophagus
  10. Describe the three phases of deglutition.
    1. deglutition
      1. voluntary stage
      2. pharyngeal stage
      3. deglutition centre
      4. esophageal stage
      5. esophageal stage of deglutition
      6. peristalsis
  11. Describe the location, anatomy, histology and functions of the stomach.
    1. stomach
      1. anatomy
      2. cardia
      3. fundus
      4. body
      5. pyloric antrum
      6. pyloric canal
      7. pylorus
      8. rugae
      9. pyloric sphincter
      10. lesser curvature
      11. greater curvature
      12. histology
        1. mucosa
        2. surface mucous cells
        3. lamina propria
        4. muscularis mucosae
        5. gastric glands lining gastric pits
        6. mucous neck cells
        7. mucus
        8. parietal cells
        9. hydrochloric acid
        10. intrinsic factor
        11. chief cells
        12. pepsinogen
        13. gastric lipase
        14. gastric juice
        15. G cells
        16. gastrin
        17. submucosa
        18. muscularis (three layers including oblique layer)
        19. serosa
      13. mechanical and chemical digestion
      14. propulsion
      15. retropulsion
      16. chyme
      17. gastric emptying
      18. proton pumps
      19. pepsin
      20. gastric lipase
  12. Describe the location, anatomy, histology and functions of the pancreas.
    1. pancreas
      1. anatomy
        1. head
        2. body
        3. tail
        4. pancreatic duct or duct of Wirsung
        5. hepatopancreatic ampulla or ampulla of Vater
        6. major duodenal papilla
        7. sphincter of the hepatopancreatic ampulla or sphincter of Oddi
        8. accessory duct or duct of Santorini
      2. histology
        1. acini
        2. pancreatic islets or islets of Langerhans
      3. composition and functions of pancreatic juice
      4. pancreatic amylase
      5. trypsin
      6. chymotrypsin
      7. carboxypeptidase
      8. elastase
      9. pancreatic lipase
      10. ribonuclease and deoxyribonuclease
      11. trypsinogen
      12. enterokinase
      13. regulation of pancreatic secretions
  13. Describe the location, anatomy, histology and functions of the liver and gallbladder.
    1. liver and gallbladder
    2. anatomy of the liver
    3. right lobe
    4. left lobe
    5. quadrate lobe
    6. caudate lobe
    7. ligamentum teres
    8. gall bladder—fundus, body, neck
    9. histology of the liver and gallbladder
      1. hepatocytes
      2. bile canaliculi
      3. bile ducts
      4. right and left hepatic ducts
      5. common hepatic duct
      6. cystic duct
      7. common bile duct
      8. sinusoids
      9. central vein
      10. lobules—hepatic and portal; hepatic acinus
    10. blood supply of the liver
    11. role and composition of bile
    12. bilirubin
    13. emulsification
    14. functions of the liver
  14. Describe the location, anatomy, histology and functions of the small intestine.
    1. small intestine
      1. anatomy
      2. duodenum
      3. jejunum
      4. ileum
      5. ileocecal sphincter
      6. histology
        1. mucosa
        2. absorptive cells
        3. goblet cells
        4. intestinal glands or crypts of Lieberkuhn
        5. Paneth cells
        6. secretin
        7. cholecystokinin (CCK)
        8. glucose dependent insulinotropic peptide (GIP)
        9. solitary lymphatic nodules
        10. aggregated lymphatic follicles or Peyer’s patches
        11. submucosa
        12. duodenal glands or Brunner’s glands
        13. muscularis
        14. serosa
        15. circular folds
        16. villus (plural is villi)
        17. lacteal
        18. microvillus (plural is microvilli)
        19. brush border
        20. intestinal juice
        21. brush border enzymes: dextrinase, maltase, sucrase, lactase, peptidases (including aminopeptidase and dipeptidase), nucleosidases and phosphatases
      7. mechanical digestion
      8. segmentations
      9. migrating motility complex (MMC)
      10. chemical digestion
        1. enzymes that digest carbohydrates
        2. enzymes that digest proteins
        3. enzymes that digest lipids
        4. enzymes that digest nucleic acids
      11. absorption in the small intestine
        1. absorption of monosaccharides
        2. absorption of amino acids, dipeptides and tripeptides
        3. absorption of lipids and bile salts
        4. micelles
        5. chylomicrons
        6. lipoprotein lipase
        7. enterohepatic circulation
        8. absorption of electrolytes
        9. absorption of vitamins
        10. absorption of water
  15. Describe the location, anatomy, histology and functions of the large intestine.
    1. large intestine
      1. anatomy
      2. cecum
      3. appendix or vermiform appendix
      4. colon
      5. ascending colon
      6. transverse colon
      7. descending colon
      8. sigmoid colon
      9. rectum
      10. anal canal
      11. anal columns
      12. anus
      13. internal anal sphincter
      14. external anal sphincter
      15. histology
        1. mucosa
        2. submucosa
        3. muscularis
        4. teniae coli
        5. haustra (singular is haustrum)
        6. serosa
      16. mechanical digestion
        1. gastroileal reflex
        2. haustral churning
        3. mass peristalsis
        4. gastrocolic reflex
      17. chemical digestion
      18. absorption and feces formation
      19. defecation reflex
      20. diarrhea
      21. constipation
  16. Describe the three phases of digestion.
    1. phases of digestion
      1. cephalic phase
      2. gastric phase
        1. neural regulation
        2. hormonal regulation
        3. gastrin
      3. intestinal phase
        1. neuroregulation
        2. enterogastric reflex
        3. hormonal regulation
      4. cholecystokinin or CCK
      5. secretin
  17. Describe the major hormones that regulate digestive activities—Table 24.8.
    1. gastrin
    2. secretin
    3. cholecystokinin (CCK)
  18. Describe the disorders listed.
    1. disorders
      1. dental caries
      2. periodontal disease
      3. peptic ulcer disease
      4. diverticulitis
      5. colorectal cancer
      6. hepatitis

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