Ch 23: The Digestive System Flashcards

1) The relatively unchanging pressure in a filling stomach is due to the contraction of the stomach oblique muscle layer.

2) The circular folds of the small intestine enhance absorption by causing the chyme to spiral, rather than to move in a straight line, as it passes through the small intestine.

3) Gastric accommodation is an example of smooth muscle plasticity.

4) Some of the microbes that often invade other organs of the body are rarely found in the stomach. The reason for this is the presence of HCl.

5) Stellate macrophages are found in the liver and are responsible for removing bacteria and worn-out cells.

6) The pharyngeal-esophageal phase of swallowing is involuntary and is controlled by the swallowing center in the thalamus and lower pons.

7) All the chemical and mechanical phases of digestion from the mouth through the small intestine are directed toward changing food into forms that can pass through the epithelial cells lining the mucosa into the underlying blood and lymphatic vessels.

8) Pepsinogen is the precursor to the gastric enzyme for protein digestion and is secreted by the parietal cells.

9) The only essential function of the stomach is to begin the digestion of proteins.

10) The major role of absorption in the ileum is to reclaim bile salts to be recycled back to the liver.

11) The peritoneum is the most extensive serous membrane in the body.

12) Peyer's patches are found in the submucosa of the distal end of the small intestine.

13) The submucosal nerve plexus provides the major nerve supply to the GI tract wall and controls GI motility.

14) The major means of propulsion through the alimentary canal is peristalsis.

15) Dentin anchors the tooth in place.

16) The digestive function of the liver is to produce bile.

17) The pancreas has both an endocrine and an exocrine function.

18) Another term for swallowing is deglutition.

19) The intrinsic ability of visceral smooth muscle to exhibit the stress-relaxation response is termed plasticity.

20) The stomach's contractile rhythm is set by pacemaker cells found in the spinal cord.

21) The major stimulus for production of intestinal fluid is distention or irritation of the intestinal mucosa by hypertonic or acidic chyme.

22) Most nutrients are absorbed through the mucosa of the intestinal villi by active transport.

23) Severe diarrhea can diminish potassium ion absorption.

24) Mumps is an inflammation of the parotid glands caused by myxovirus.

25) Fats significantly delay the emptying of the stomach through hormonal and neuronal signals.

26) The soft palate reflexively opens the nasopharynx to allow the passage of food, which is now called a bolus.

27) When swallowing, the epiglottis covers the larynx.

28) Most gastric ulcers are due to excessive production of hydrochloric acid.

1) The enterohepatic circulation reabsorbs bile salts in the distal portion of the small intestine (ileum). All of the following statements about the enterohepatic circulation are true except one. Select the statement below that is not true of the enterohepatic circulation? A) Reabsorbing bile salts in the ileum gives more time to emulsify lipid and aid in their absorption within a greater length of the small intestine. B) All of the components of bile are recycled by this circulation. C) Reabsorption of bile salts reduces the need to synthesize new bile salts. D) The reabsorption of bile salts allows them to be reused within new bile.

2) Which of the following is the best illustration of the difference between metabolism and digestion? A) Digestion has a wide variety of chemical reactions while metabolism is restricted to only a few reaction types. B) Digestions must happen first for metabolism to follow it. C) Metabolism comprises all of the chemical reactions preformed with in the body while digestion is only the breakdown of food within the G.I. Tract. D) Digestion requires enzymes for it to take place while metabolism does not necessarily need or use them.

3) Which of the following is least involved in the mechanical breakdown of food, digestion or absorption of nutrients? A) the oral cavity B) the esophagus C) large intestine D) the small ingestion

4) Which of the organs listed below is involved in all of the following processes: secretion, mechanical breakdown of food, digestion and absorption? A) the stomach B) the esophagus C) the sigmoid colon D) the large intestines

5) Which of the following is the best explanation of the benefit in the digestive system having the largest collection of lymphoid tissue (MALT) at the distal end of the small intestine? A) The alkaline secretion of the small intestine aid in the growth of bacteria and must be controlled. B) The body will actively excrete pathogens out the body, into the digestive system to be removed from the body in feces. C) The huge numbers of bacteria living in the large intestine must be prevented from entering the lumen of the small intestine and being absorbed with food's nutrients into the blood stream. D) The digestive systems first and foremost job is to digest and absorb nutrients so it puts off immunity for last.

6) Bile salts bind at their hydrophobic regions to large fat globules within the chyme that enters the duodenum. Bile salts break up the fat globule into smaller fat droplets. This role of bile salts is best described as ________. A) lipid emulsification B) lipid absorption C) lipid ingestion D) lipid digestion

7) A doctor consulting a patient that recently has had their gall bladder removed would likely advise ________. A) increasing unsaturated fats while eliminating trans fats in their diets B) a low to no carb diet C) fewer, but larger meals D) eating foods that are low in fat

8) A ruptured appendix is life threatening because ________. A) it is likely to cause severe internal bleeding B) the large intestine will no longer be able to receive digested material from the small intestine C) loss of the appendix's function will cause an immune deficiency in the digestive system D) it is likely to cause massive infection of the abdominopelvic cavity

9) All but one of the following is a function of the low pH found in the stomach. Select the description below that does not reflect a role of stomach acid. A) The stomach's acid catabolically breaks down food stuffs in preparation for absorption. B) Stomach acid denatures proteins making the poly peptide chain more accessible to pepsin digestive enzymes. C) Many potentially harmful bacteria will be prevented entry to the small intestine by stomach acid. D) Low pH converts pepsinogen to its active form of pepsin, preventing the protease enzyme from digesting the cells that produce it.

10) Fat absorption through the plasma membrane of epithelial cells ________. A) Is accomplished by cotransporters that use the concentration gradient of Na+ outside of the cells B) requires vesicular, active transport of the relatively large fatty acids and monoglyceride C) occurs by simple diffusion because lipids are able to penetrate the hydrophobic fatty acid tails within the plasma membrane D) requires enzymes attached to the brush border to further breakdown the fats

11) Select the best explanation for why protease enzymes are secreted in inactive forms. A) Inactive enzymes will simply be expelled with the feces if no protein is present in the digesting food, this will help to conserve energy. B) The immunoglobulins protecting the digestive tract would be digested without proper regulation of protein digesting enzymes. C) The enzymes would digest each other if they were not properly regulated. D) The cells producing inactive enzymes are themselves protected from the enzymes until they are safely within the lumen of the GI tract.

12) Select the description below that illustrates a difference between a sphincter and circular muscle. A) A sphincter is a thickening of circular muscle that can prevent the movement of digesting materials while circular muscle is involved in propulsion digesting material. B) Sphincters are found throughout the GI tract while circular muscle is found only in the proximal portion of the GI tract. C) A sphincter is composed of smooth muscle while circular muscle is composed of skeletal muscle tissue. D) Sphincters are found in the proximal portion of the GI tract while circular muscle is found in the distal portions.

13) In the enteric nervous system, a long reflexive pathway has an advantage over a short reflexive pathway in the fact that ________. A) long reflexive pathways last much longer than short reflexive pathways B) long reflexive pathways can respond throughout the entire length of the GI tract while short reflexive pathways can only respond in the proximal end C) long reflexive pathways are quicker to respond than short reflexive pathways D) long reflexive pathways can be stimulated by things outside of the GI tract

14) The sight of food can trigger a series of events that results in the release of gastric juice. All but one of the following is true in regards to the previous statement. Select the one answer that is not true. A) This prepares the stomach for food before its arrival in the stomach. B) This is an example of a long reflexive pathway. C) The motor nerves of this pathway are part of the sympathetic division of the autonomic nervous system. D) The cerebral cortex, hypothalamus and medulla oblongata are all involved in processing the stimulatory information.

15) All of the following are true of swallowing (deglutition) except one. Select the statement that is not true of swallowing. A) The involuntary portion of swallowing takes place in the pharynx. B) The mouth, pharynx and esophagus all take part in swallowing. C) The epiglottis assists in propelling food into the trachea. D) The voluntary phase of swallowing takes place within the mouth.

16) Some antacid drugs block histamine receptors, resulting in reduction of the production and excretion of stomach acid. These drugs have the biggest effect on which of the following? A) surface epithelial cells B) chief cells C) mucous neck cells D) parietal cells

17) Generally the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________. A) speed the churning of the stomach B) increases the output of stomach acid C) speed the activity of the jejunum D) slow the activities of the stomach

18) Generally the hormones secretin and cholecystokinin which are released by duodenal enteroendocrine cells will ________. A) decrease the activities of the accessory digestive organs B) increases stomach emptying C) increase the force of stomach contractions D) increase the release of digestive enzymes and bile

19) Select the one response below that would not result from a drug that blocks histamine receptors in the cells lining the stomach. A) It would reduce the symptoms of heartburn. B) It would cause the release of secretin and cholecystokinin. C) It would lower the activity of parietal cells. D) It would raise the pH of the stomach.

20) Proteins entering the stomach act as a buffer raising pH. Rising pH stimulates the activity of G-cells in the lining of the stomach. All of the following but one will occur. Select the statement below that would not occur. A) More stomach acid will be produced and secreted. B) A positive feedback response will be initiated and G-cell activity will continue to go up. C) Protein digestion will be enhanced. D) Digestive enzymes will be released.

21) The mechanical and chemical receptors that control digestive activity are located ________. A) in the walls of the tract organs B) in the glandular tissue that surround the organ lumen C) in the oral cavity D) in the pons and medulla

22) The function of the hepatic portal circulation is to ________. A) return glucose to the general circulation when blood sugar is low B) carry toxins to the kidney for disposal through the urinary tract C) distribute hormones throughout the body D) collect absorbed nutrients for metabolic processing in the liver

23) The chemical and mechanical processes of food breakdown are called ________. A) secretion B) ingestion C) absorption D) digestion

24) When we ingest large molecules such as lipids, carbohydrates, and proteins, they must undergo catabolic reactions whereby enzymes split these molecules. This series of reactions is called ________. A) mechanical breakdown B) absorption C) secretion D) chemical digestion

25) The sheets of peritoneal membrane that hold the digestive tract in place are called ________. A) mucosal lining B) lamina propria C) serosal lining D) mesenteries

26) From the esophagus to the anal canal, the walls of every organ of the alimentary canal are made up of the same four basic layers. Arrange them in order from the lumen. A) serosa, mucosa, submucosa, and muscularis externa B) mucosa, submucosa, muscularis externa, and serosa C) submucosa, serosa, muscularis externa, and mucosa D) muscularis externa, serosa, mucosa, and submucosa

27) Which of the following is not a factor that helps create the stomach mucosal barrier? A) replacing of damaged epithelial mucosa cells B) thick coating of bicarbonate-rich mucus C) secretion of pepsinogen D) tight junctions of epithelial mucosa cells

28) What part of the tooth bears the force and resists the friction of chewing? A) crown B) enamel C) cementum D) pulp

29) The capillaries that nourish the epithelium and absorb digested nutrients lie in the ________. A) adventitia B) lamina propria C) submucosa D) serosa

30) Choose the incorrect statement regarding bile. A) Bile functions to emulsify fats. B) Bile contains enzymes for digestion. C) Bile functions to carry bilirubin formed from breakdown of worn-out RBCs. D) Bile is both an excretory product and a digestive secretion.

31) The absorptive effectiveness of the small intestine is enhanced by increasing the surface area of the mucosal lining. Which of the following accomplish this task? A) the vast array of digestive enzymes B) the rugae and haustra C) villi, and microvilli D) Brunner's glands and Peyer Patches

32) Select the statement that is true concerning primary teeth. A) There are 20 primary teeth, and by 24 months of age most children have all 20. B) There are 27 primary teeth, and the molars are permanent. C) There are 32 primary teeth, and by 36 months of age, most children have all 32. D) There are 24 primary teeth, and no new primary teeth appear after 13 months.

33) Which of the following is true concerning the number and type of permanent teeth? A) There are 27 permanent teeth, and the first molars are usually the last to emerge. B) There are 32 permanent teeth, and the wisdom teeth are the last to emerge. C) The number of upper permanent teeth is not equal to the number of lower permanent teeth. D) The number of permanent teeth is always equal to the number of primary teeth.

34) Which of the following is not true of saliva? A) moistens food and aids in compacting of the bolus B) cleanses the mouth C) contains enzymes that begin the breakdown of carbohydrates D) contains acids which aid in chemical digestion

35) The solutes contained in saliva include ________. A) mucin, lysozyme, electrolytes, salts, and minerals B) only proteases and amylase C) electrolytes, digestive enzyme, mucin, lysozyme, wastes, and IgA D) only salts and minerals

36) The bolus is liquefied in the ________ and it is now called chyme. A) esophagus B) stomach C) small intestine D) mouth

37) Peristaltic waves are ________. A) churning movements of the gastrointestinal tract that aid in mechanical breakdown of chyme B) segmental regions of the gastrointestinal tract C) waves of muscular contractions that propel contents from one point to another D) pendular movements of the gastrointestinal tract

38) Pepsinogen, an inactive digestive enzyme, is secreted by the ________. A) parietal cells of the duodenum B) goblet cells of the small intestine C) Brunner's glands D) chief cells of the stomach

39) You have just eaten a meal high in complex carbohydrates. Which of the following enzymes will help to digest the meal? A) amylase B) trypsin C) gastrin D) cholecystokinin

40) The ducts that deliver bile and pancreatic juice from the liver and pancreas, respectively, unite to form the ________. A) hepatopancreatic ampulla B) bile canaliculus C) pancreatic acini D) portal vein

41) Short-chain triglycerides found in foods such as butterfat molecules in milk are split by a specific enzyme in preparation for absorption. Which of the following enzymes is responsible? A) pepsin B) amylase C) lipase D) chymotrypsin

42) Hepatocytes do not ________. A) store fat-soluble vitamins B) produce digestive enzymes C) process nutrients D) detoxify toxic chemicals

43) Chief cells ________. A) produce gastrin B) produce mucin C) produce pepsinogen D) produce HCl

44) Chemical digestion reduces large complex molecules to simpler compounds by the process of ________. A) catabolism B) fermentation C) mastication D) anabolism

45) The ________ contains lobules with sinusoids (lined with macrophages) that lead to a central venous structure. A) stomach B) spleen C) liver D) pancreas

46) Digestion and absorption of which of the following would be affected the most if the liver were severely damaged? A) starches B) proteins C) lipids D) carbohydrates

47) The dental formula for an adult is 2-1-2-3. What does the 1 stand for? A) premolar tooth B) canine tooth C) molar tooth D) incisor tooth

48) The lamina propria is composed of ________. A) dense irregular connective tissue B) dense regular connective tissue C) reticular connective tissue D) loose connective tissue

49) Which of the following is (are) not important as a stimulus in the gastric phase of gastric secretion? A) distention B) peptides C) low acidity D) carbohydrates

50) The function of goblet cells is to ________. A) provide protection against invading bacteria and other disease-causing organisms that enter the digestive tract in food B) secrete buffers in order to keep the pH of the digestive tract close to neutral C) produce mucus that protects parts of the digestive organs from the effects of powerful enzymes needed for food digestion D) absorb nutrients from digested food and store them for future use

51) Which of the following is an essential role played by large intestine bacteria? A) absorb bilirubin B) synthesize vitamins C and D C) fermentation of indigestible carbohydrates D) produce gas

52) Nervous control of gastric secretion is provided by ________. A) somatic neurons in the spinal cord B) the vagus nerve and enteric plexus C) the reticulospinal and vestibulospinal tracts D) the rubrospinal tracts

53) Which of the following are types of papillae on the tongue that contain taste buds? A) palatine and circumvallate B) fungiform, circumvallate, and filiform C) circumvallate and filiform D) fungiform and circumvallate

54) Which of the following produce intrinsic factor? A) mucous neck cells B) zymogenic cells C) enteroendocrine cells D) parietal cells

55) Which of the following enzymes would be most active in the presents of a high concentrations of protein fragments? A) lipase B) trypsin C) amylase D) dextrinase

56) A child with restricted tongue movement may have a surgery that involves the cutting of the ________. A) lingual frenulum B) uvula C) palatine tonsils D) terminal sulcus

57) What stomach secretion is necessary for normal hemoglobin production in RBCs? A) pepsinogen B) gastric lipase C) intrinsic factor D) HCl

58) Select the correct statement about the regulation of gastric secretion. A) Gastric secretion can be stimulated before food has entered the mouth. B) The presence of food in the stomach prevents hormonal control of gastric secretion. C) Vagus stimulation of the stomach results in decreased secretion of gastric juice. D) Gastric secretion is enhanced by very low pH (below a pH of 2).

59) Paneth cells ________. A) secrete hormones B) secrete digestive enzymes C) secrete bicarbonate ions D) secrete enzymes that kill bacteria

60) Select the correct statement about absorption. A) Eighty percent of ingested materials have been absorbed by the end of the large intestine. B) In the rare case that intact, whole proteins are transported across the mucosal endothelium, an immune response may be generated. C) Carbohydrates diffuse across the mucosal endothelium and are then actively transported into blood capillaries. D) Amino acid transport is linked to chloride transport.

61) Select the correct statement about electrolyte absorption. A) Chlorine ion absorption is coupled to glucose and amino acid transport. B) If vitamin B is not present, calcium is not absorbed. C) Iron and calcium are absorbed mostly by the duodenum. D) Potassium moves across the epithelium by active transport.

62) The ingestion of a meal high in fat content would cause which of the following to occur? A) This type of food would cause secretion of gastrin to cease, resulting in faster gastric emptying. B) Increased production of trypsinogen. C) Bile would be released from the gallbladder to emulsify the fat in the duodenum. D) The acid secretions from the stomach would be sufficient to digest this food but may cause heartburn.

63) Hormones or paracrines that inhibit gastric secretion include ________. A) histamine B) secretin C) ACh D) gastrin

64) Which of these is not part of the splanchnic circulation? A) hepatic portal vein B) superior mesenteric artery C) celiac artery D) inferior vena cava

65) Which of these is not a component of saliva? A) lysozyme B) metabolic waste C) defensins D) a cyanide derivative