Digestive System

  1. The main fuctions of the digestive system (3)
    • Takes in food and breaks it down into nutrient molecules
    • absorbs nutrients into the bloodstream
    • excretes the indigestible remains and metabolic products
  2. What are the organs of the digestive system; two main groups
    alimentary canal (nourish) and accessory digestive organs.
  3. The alimentary canal is also known as what?
    GI (gastrointestinal tract) or gut
  4. This is the a continuous, muscular tube, about 20-25ft long
    alimentary canal
  5. This is the a continuous, muscular tube, about 20-25ft long
    alimentary canal
  6. What is the function(s) of the alimentary canal?
    It digests food and absorbs through its lining into the blood
  7. The organs of the alimentary canal are? (6)
    the mouth, pharynx, esophagus, stomach, small and large intestine
  8. The large intestine leads to where?
    the terminal opening, or anus.
  9. The accessory digestive organs are what (3) and what digestive glands (3)?
    The teeth, tongue, gallbladder, and a number of large digestive glands (the salivary glands, liver, and pancreas)
  10. What is the fuction of the accessory digestive organs?
    To produce a variety of secretions that assist in the breakdown of food.
  11. The processing of food by the digestive system involves six essential activities, what are they?
    Ingestion, Propulsion, Mechanical digestion, Chemical digestion, Absorption and Defection.
  12. What is the function of ingestion?
    To taking food into the digestive tract, usually via the mouth.
  13. What is the function of propulsion?
    To move food through the alimentary canal (pushing forward)
  14. What is the major means of propulsion? This involves alternate wave of contraction and relaxation of the muscles in the organ walls.
  15. The function of mechanical digestion?
    to prepare food for chemical digestion by enzymes.
  16. This type of digestive process includes chewing, mixing of food with saliva by the tongue, churning food in the stomach, and segmentation, or rhythmic local constrictions of the intestine, mixing digestive juices.
    Mechanical digestion
  17. The function of Chemical digestion is what? (it begins in the mouth and is complete in the small intestine)
    to break down food by enzymes
  18. This digestive process moves products into the blood or lymph? (the small intestine is the major site for this)
  19. This digestive process eliminates the indigestible substances via the anus in the form of feces.
  20. The abdominal aorta branches off into arteries for blood supply to where?
    the spleen, liver, and stomach, small and large intestines
  21. How much of the of the cardiac output is in the digestive organs
    1/4 of the output
  22. The Hepatic portal circulation supplies blood to where?
    the liver
  23. This circulation collects nutrient-rich venous blood draining from the digestive viscera and delivers it to where?
    The liver
  24. The liver collects the nutrients for metabolic processing or for storage before releasing them to where?
    the bloodstream for general cellular use.
  25. From the esophagus to the anal canal, the walls of the alimentary canal have the same four basic layers what are they? (4)
    mucosa, submucosa, muscularis externa and serosa
  26. What is the inner most layer of the alimentary canal
    mucosa or mucous membrane
  27. This is a moist epithelial membrane lining the GI lumen.
    The mucosa or mucous membrane
  28. The mucosa or mucous membranes' major function are? (3)
    secretion, absorption, and protection against infectious disease.
  29. The layer of the alimentary canal that has dense connective tissue containing blood and lymphatic vessels, lymphoid follicles, and nerve fibers.
    The submucosa
  30. This submucosa layer of the alimentary canal has abundant elastic fibers for what purpose?
    enables the stomach to regain its normal shape after temporarily storing a large meal.
  31. The submucosa layer of the alimentary canal has a rich supply of blood supply to supply surrounding tissues. True or False
  32. This layer of the alimentary canal surrounds the submucosa?
    The muscularis externa
  33. The muscularis externa layer of the alimentary canal is responsible for what? (2)
    segmentation and peristalsis
  34. In several places along the tract, the circular layer thickens, forming sphincters controlling food passage in what layer of the alimentary canal?
    The muscularis externa
  35. The serosa is the the intermost layer of the alimentary canal? True or false
    False: the serosa is the outermost layer of the alimentary canal
  36. This layer of the alimentary canal is a single layer of squamous epithelial cells?
    The Serosa
  37. The mouth is also known as this?
    the oral cavity, or buccal cavity
  38. This provides a rough surface for which the tongue forces food during chewing, and forward motion for swallowing
    The palate
  39. The tongue initiates what? (2)
    movement and swallowing
  40. The salivary glands secrete what?
  41. The function(s) of saliva is what? (4)
    to cleanse the mouth, dissolves food chemicals so that they can be tasted, moistens food and aids in compacting it into a bolus, and contains enzymes that begin the chemical breakdown of starchy foods).
  42. What percentage of Saliva is water?
    97 to 99.5%
  43. What is the pH of saliva
    6.75 - 7.00 slightly acidic
  44. Saliva's solutes include electrolyes such as? (5)
    Sodium, potassium, chloride, phosphate, and bicarbonate
  45. Saliva has a digestive enzyme called what?
    salivary amylase
  46. All of the following; the proteins mucin, Lysozyme, IgA and metabolic wastes (urea and uric acid) can be found where?
    In saliva
  47. These lie in sockets (alveoli) in the gum-covered margins of the mandible and maxilla?
  48. Another name for chewing?
  49. This is done by opening and closing jaws and moving the teeth from side to side using the tongue to move the food between teeth?
    chewing or mastication
  50. From the mouth, food passes posteriorly into this?
  51. After the food passes through the oropharynx and then to the what?
    the laryngopharynx
  52. The oropharynx and laryngopharynx are both uncommon passageways for food, fluids, and air. True or False
    False: its a common passageway
  53. The mucosa layer of this organ, (part of the alimentary canal) contains a friction-resistant stratified squamous epithelium with mucus-producing glands.
    The pharynx
  54. The muscle layers propel food into the esophagus by contractions from this area of the alimentary canal?
  55. This is a muscular tube about 25 cm (10 inches) long?
    The esophagus
  56. The esophagus does not collapsed when not involved in food propulsion. True or false
    Fales: the esophagus is collapsed when not involved in food propulsion
  57. After food moves through the laryngopharynx, it is routed into this?
    The esophagus
  58. After food moves through the laryngopharynx, it is routed into this posteriorly as the epiglottis closes off the larynx to food entry.
    the esophagus
  59. Simple columnar epithelium secretes enzymes for digestion in this organ of the alimentary canal
    The esophagus
  60. Where the esophagus joins the stomach is called what?
    the cardiac orifice, it acts as a sphincter
  61. This is known as a temporary "storage tank"
  62. What is the function of the stomach?
    to begin the chemical breakdown of proteins and food
  63. In the stomach food is converted to a creamy paste called what?
  64. The stomach it self quite movable, this is unexpected why?
    the stomach is relatively fixed at both ends
  65. This is considered the major digestive organ
    The small intestine
  66. This is a convoluted tube extending from the pyloric sphincter in the epigastric region to the ileocecal valve?
    The small intestine
  67. The small intestine extends from the pyloric sphincter in the epigastric region to the ileocecal valve then joins what?
    the large intestine
  68. This is the longest part of the alimentary canal
    The small intestine
  69. The small intestine is about half the diameter of the large intestine. true or false
  70. What is the diameter of the small intestine?
    it ranges from 2.5 to 4 cm (1–1.6 inches).
  71. How long is the small intestine?
    about 2–4 m (7–13 ft) long in a live person
  72. What are the three subdivisions of the small intestines
    the duodenum, the jejunum and the ileum
  73. The duodenum is immovable, curves around the head of the what?
  74. The duodenum is a subdivision of the small intestine and is how long?
    10 inches
  75. The bile duct with bile from the liver, and the main pancreatic duct, carrying pancreatic juicefrom the pancreas, unite in the wall of the duodenum in a bulblike point called what?
    the hepatopancreatic ampulla
  76. The hepatopancreatic ampulla opens into the duodenum via the what?
    duodenal papilla
  77. The entry of bile and pancreatic juice into the duodenum is controlled by a muscular valve called what?
    the hepatopancreatics phincter, or sphincter of Oddi
  78. The jejunum("empty"), a subdivision of the stomach, is how long?
    about 2.5 m (8 ft) long
  79. This extends from the duodenum to the ileum, a subdivision of the stomach
  80. The ileum("twisted"), a subdivision of the stomach is how long?
    approximately 3.6 m (12 ft) in length
  81. The ileum("twisted"), a subdivision of the stomach, joins the large intestine where?
    at the ileocecal valve
  82. The jejunum and ileum hang in coils in the central and lower part of the abdominal cavity, suspended from where?
    the posterior abdominal wall
  83. These are fingerlike projections of the mucosa
  84. The function of the epithelial cells of the Villi is what?
  85. In the core of each villus is a dense capillary bed called?
  86. These are tiny projections of the plasma membrane of the absorptive cells of the mucosa?
  87. These give the mucosal surface a fuzzy appearance called the brush border.
  88. These contains enzymes (brush border enzymes) for complete digestion of carbohydrates and proteins.
  89. Peyer’spatches decrease or increase in numbers at the end of the small intestine?
  90. Peyer's Patches are in abundance at the end of the small intestine. Why is this?
    they are involved in preventing bacteria from entering the bloodstream.
  91. How much intestinal juice is produced by the intestinal glands daily?
    1 to 2 L of juice
  92. The major stimulus for the production of intestinal juice is what?
    distension or irritation of the intestinal mucosa by chyme
  93. What is the normal pH of intestinal juice?
    slightly alkaline 7.4 - 7.8
  94. Intestinal juice is isotonic with blood plasma. true or false
  95. This is largely water, but it also contains some mucus, secreted by the duodenal glands and by goblet cells of the mucosa.
    intestinal juice
  96. This fluid does not contain much enzymes
    intestinal juice
  97. In this accessory organ, it's digestive function is to produce bile for export to the duedenum.
    the liver
  98. Bile leaves the liver through several bile ducts that fuses to the large common hepatic duct, then to what?
    the duodenum
  99. Bile leaves the liver through several ducts. Along its course ducts fuse with the cystic duct to drain what? and form what duct?
    draines the gallbladder to form the bile duct
  100. Where is bile stored?
    the gallbladder
  101. This is a yellow-green, alkaline solution containing salts, pigments, cholesterol, and a variety of electrolytes.
  102. Salts and phospholipids from this solution aid the digestive process.
  103. Bile salts function is to emulsify fats, this is needed to do what?
    distribute the fats throughout the watery intestinal contents
  104. Emulsified fats are easily accessible to fat-digesting enzymes called what?
  105. The chief bile pigment is what?
  106. This is a waste product of the heme of hemoglobin formed during the breakdown of worn-out erythrocytes.
  107. This is a protein, released by intestinal cells exposed to fatty chyme, stimulates liver cells to secrete bile.
  108. Yellow bile pitments accumulate in the blood and eventually are deposited in the skin causing the skin to become yellow also known as
  109. This is a thin-walled green muscular sac, is an accessory organ?
    The gallbladder
  110. The gallbladder is how long?
    about 10 cm (4 inches) long.
  111. This snuggles in a shallow fossa on the ventral surface of the liver
    The gallbladder
  112. This stores bile that is not immediately needed for digestion
    The gallbladder
  113. While storing bile this concentrates the bile by absorbing some of its water and ions.
    The gallbladder
  114. When the gallbladder's muscular wall contracts, bile is expelled into its duct, the cystic duct, and then flows where?
    into the bile duct.
  115. This is a soft, tadpole-shaped gland that extends across the abdomen
    The pancrease
  116. This accessory digestive organ is encircled by the C-shaped duodenum
    The pancrease
  117. The pancrease produces enzymes that break down all foodstuffs, which then goes where?
    to the duodenum
  118. The pancrease secretes this, via pancreatic duct then fuses with bile duct empty into the duodenum.
    pancreatic juice
  119. Within the pancreas are clusters of secretory cells called what?
    the acini
  120. The pancrease secrete granules for fermenting. What are the granules called?
    zymogen granules
  121. Approximately how much pancreatic juice is produced daily?
    1200 to 1500 ml produced daily
  122. Pancreatic juice is a clear, and has water and enzymes. What is its pH
    pH 8
  123. The pancrease produces an enzyme called what? the enzyme is produced and released in inactive forms, and then activated when needed
    Pancreatic proteases (protein-digesting enzymes)
  124. Once the inactivated enzymes are released from the pancrease, within the duodenum these enzymes are activated to what?
    Trypsinogen then to Trypsin then back to more trypsinogen which activates carboxypeptidase and chymotrypsin
  125. These are pancreatic enzymes secreted in an active form? (3)
    Amylase(on carbohydrates), lipases(on fats), and nucleases(on nucleic acid)
  126. This frames the small intestine on three sides and extends from the ileocecal valve to the anus.
    The large intestine
  127. The diameter and length of the large intestine?
    about 7cm in diameter and 1.5 m long
  128. This main function of the large intestine is what? (3)
    absorb most of the remaining water from indigestible food residues (delivered to it in a fluid state), store the residues temporarily, and then eliminate them from the body as semisolid feces(fe′sē).
  129. This is a double layer of peritoneum—a sheet of two serous membranes fused back to back
  130. Most of the bacteria in the GI system are dead, how many species are there?
    over 700 species
  131. These bacteria colonize in the colon, metabolize proteins and ferment indigestible carbohydrates (ex. cellulose)
    bacterial flora
  132. What bacteria synthesize B complex vitamins and most of the vitamin K (blood clotting).
    Bacterial flora
  133. B12 is an essential vitamin synthesized by the gut by what bacteria
    bacterial flora
  134. Most enteric bacteria coexist peacefully (mutualism) with their host as long as they remain where?
    in the gut lumen
  135. The rectum is usually empty, but when feces are forced into it by mass movements, stretching of the rectal wall initiates what?
    the defecation reflex
  136. This is a spinal cord–mediated parasympathetic reflex that causes the colon and the rectum to contract, the internal anal sphincter to relax, and the external anal sphincter to contract (initially). What is this reflex?
  137. Eventhough feces are forced into the anal canal, how can defecation can be delayed?
    a message reaches the brain allowing us to decide whether the external (voluntary) anal sphincter should be opened or remain constricted to stop feces passage temporarily.
  138. What vitamins are absorbed by the small intestines and what vitamins are absorbed by the large instestine?
    The small intestine absorbs dietary vitamins, and the large intestine absorbs some of the K and B vitamins
  139. What vitamins are absorbed by the small intestines and what vitamins are absorbed by the large instestine?
    The small intestine absorbs dietary vitamins, and the large intestine absorbs some of the K and B vitamins
  140. What vitamins are absorbed by the small intestines and what vitamins are absorbed by the large instestine?
    The small intestine absorbs dietary vitamins, and the large intestine absorbs some of the K and B vitamins
  141. What vitamins are absorbed by the small intestines and what vitamins are absorbed by the large instestine?
    The small intestine absorbs dietary vitamins, and the large intestine absorbs some of the K and B vitamins
  142. What vitamins are absorbed by the small intestines and what vitamins are absorbed by the large instestine?
    The small intestine absorbs dietary vitamins, and the large intestine absorbs some of the K and B vitamins
  143. What vitamins dissolve in dietary fats, become incorporated into the micelles, and move across the villus epithelium by passive diffusion.
    Fat-soluble vitamins (A, D, E, and K)
  144. What vitamins are absorbed easily by diffusion or via specific active or passive transporters.
    Most water-soluble vitamins (B vitamins and vitamin C)
  145. After binding with this vitamin, The intrinsic factor complex is produced by the stomach, it then binds to specific mucosal receptor sites in the terminal ileum, which trigger its active uptake by endocytosis. What is the vitamin?
  146. Iron and calcium absorption is largely limited to what area?
    the duodenum
  147. Absorption of these ions in the small intestine is coupled to active absorption of glucose and amino acids.
    sodium ion
  148. These electrolytes move across the intestinal mucosa passively by facilitated diffusion
    Potassium ions
  149. Calcium absorption is closely related to blood levels of ionic calcium and what vitamin in the small intestine
  150. How much water enters the small intestine daily?
    Approximately 9 L of water
  151. Water is the most abundant substance in chyme. What percentage of water is absorbed in the small intestine by osmosis.
  152. What is the normal rate of water absorption per hour?
    300 to 400 ml
  153. Water moves freely in both directions across the intestinal mucosa, by what active transport?
Card Set
Digestive System
Chapter 23:Digestive System