Gastrointestinal System (Pearson MyLab & Mastering A&P) Flashcards
The propulsive function that occurs in the esophagus is called _________.
- defecation
- segmentation
- ingestion
- swallowing
- peristalsis
peristalsis
The _________ is the first segment of the small intestine.
- jejunum
- ileum
- colon
- duodenum
duodenum
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 _______.
- mechanical breakdown
- secretion
- absorption
- chemical digestion
chemical digestion
Rationale: It is the type of digestion which occurs due to enzymes that start right from the mouth with the help of amylase enzyme. Some of it occurs in the stomach, but the major part is completed in the small intestine.
How would you classify chewing food?
- propulsion
- digestion
- ingestion
- mechanical breakdown
mechanical breakdown
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?
- mucous neck cells
- surface epithelial cells
- parietal cells
- chief cells
parietal cells
The function of the hepatic portal circulation is to ________.
- carry toxins to the kidney for disposal through the urinary tract
- return glucose to the general circulation when blood sugar is low
- distribute hormones throughout the body
- collect absorbed nutrients for metabolic processing in the liver
collect absorbed nutrients for metabolic processing in the liver
Which of the following is NOT a function of the large intestine?
- absorption of vitamins
- absorption of water
- absorption of electrolytes
- production of intrinsic factor
production of intrinsic factor
Which of the following is not a secretion of the pancreas?
- bicarbonate
- insulin
- nutrient digesting enzymes
- bile
bile
Rationale: Bile is secreted by the liver.
Which layer of the alimentary canal is constructed from either stratified squamous or simple columnar epithelium?
- aserose
- mucosa
- muscularis externa
- submucosa
mucosa
The bolus is liquefied in the _______ and it is now called chyme.
- small intestine
- mouth
- stomach
- esophagus
stomach
The ________ circulation drains all of the organs of the digestive system.
- peritoneal
- hepatic portal
- visceral
- solanchnic
hepatic portal
Rationale: The hepatic portal circulation drains all of the blood from the digestive organs and routes that blood through the liver for processing.
The sheets of peritoneal membrane that hold the digestive tract in place are called ________.
- serosal lining
- mucosal lining
- lamina propria
- mesenteries
mesenteries
Which organ of the digestive tract is the body’s major digestive organ?
- stomach
- liver
- small intestine
- large intestine
small intestine
The outermost tissue layer of the alimentary canal is the ________.
- muscularis
- serosa
- submucosa
- mucosa
serosa
Which cells in the small intestine’s mucosa secrete mucus?
- goblet cells
- enteroendocrine cells
- absorptive cells
- Paneth cells
goblet cells
What stomach secretion is necessary for normal hemoglobin production in RBCs?
- gastric lipase
- intrinsic factor
- pepsinogen
- HCI
intrinsic factor
Bile is stored and concentrated in the _______.
- stomach
- gallbladder
- liver
- pancreas
gallbladder
In order to prevent self-digestion of the pancreas, activation of pancreatic proteases occurs in the __________.
- gallbladder
- liver
- pancreas
- duodenum
- stomach
duodenum
Rationale: The pancreatic duct empties into the duodenum, where activation of proteases occurs. Secreting initially inactive forms of proteases prevents self-digestion of the pancreas.
During deglutition, the bolus passes into the stomach from the esophagus through the __________.
- pyloric sphincter
- gastroesophageal sphincter
- ileocecal valve
- esophageal sphincter
- urethral sphincter
gastroesophageal sphincter
Rationale: The gastroesophageal sphincter is the junction between stomach (gastro-) and esophagus. A loose gastroesophageal sphincter can cause heartburn or acid reflux.
During the intestinal phase of gastric regulation, __________.
- the enterogastric reflex is turned off
- hormones reduce chief cell activity
- the stomach is initially stimulated and later inhibited
- the gastroenteric reflex reduces stomach activity
- secretin causes more HCl release
the stomach is initially stimulated and later inhibited
What intestinal structure(s) consist(s) of protective aggregated nodules of lymphocytes and macrophages?
- Peyer’s patches
- the muscularis mucosae
- the gastric pits
- the intestinal crypts
- the muscularis externa
Peyer’s patches
Rationale: Peyer’s patches, which contain lymphocytes and macrophages, increase in number toward the end of the ileum, indicating that this region is rife with bacteria that must be prevented from entering the bloodstream.
What are the main organic molecules digested in the stomach?
- proteins
- lipids
- salts
- nucleic acids
- carbohydrates
proteins
Rationale: The main enzyme produced by the stomach is pepsin, which digests protein (gastric lipases are only of minor importance).
The main propulsive force that occurs in the majority of the alimentary canal is called __________.
- ingestion
- swallowing
- defecation
- peristalsis
- segmentation
peristalsis
Rationale: Peristalsis occurs as alternating waves of contraction and relaxation and serves to propel food down the tract.
Which of the following is a characteristic of the large intestine?
- It is the site for acid neutralization.
- It is longer than the small intestine.
- It contains epiploic appendages.
- It has villi.
- It provides no absorptive function.
It contains epiploic appendages.
Rationale: Suspended from the large intestine are epiploic appendages, which are small fat-filled pouches of visceral peritoneum.
Which regulatory chemical stimulates gastric gland activity and motility?
- histamine
- gastrin
- secretin
- CCK
- vasoactive peptide
gastrin
Rationale: Gastrin is the major stomach hormone. Both the stomach and the small intestine produce this chemical.
Which sequence below represents the correct order of the tunics of the GI tract, starting from the layer adjacent to the lumen and moving superficially?
- serosa, mucosa, muscularis externa, submucosa
- mucosa, submucosa, muscularis externa, serosa
- submucosa, mucosa, muscularis externa, serosa
- muscularis externa, serosa, submucosa, mucosa
- mucosa, muscularis externa, submucosa, serosa
mucosa, submucosa, muscularis externa, serosa
Rationale: The mucosa is the layer that lines the lumen; it is followed by the submucosa, muscularis externa, and serosa.
What substances from different organs would mix together at the hepatopancreatic ampulla?
- secretin and CCK
- HCl and pepsin
- bile and pancreatic enzymes
- brush border enzymes and intrinsic factor
bile and pancreatic enzymes
Rationale: Bile and pancreatic enzymes mix at the hepatopancreatic ampulla.
What would be the effect of stripping the small intestines of their villi?
- The large intestine would take over as the primary absorptive site.
- decreased surface area for absorption
- Salivary amylase secretion would increase.
- A duodenal ulcer would develop.
decreased surface area for absorption
Rationale: Decreased intestinal surface area would lead to decreased absorption, leading to a long list of problems such as malnutrition, dehydration, diarrhea, and electrolyte imbalance.
Which of the following products does the stomach produce?
- pepsinogen and secretin
- mucus and amylase
- HCl and intrinsic factor
- bile and trypsin
HCl and intrinsic factor
Rationale: HCl, IF, mucus, and pepsinogen (pepsin) are products of the stomach.
The final product of carbohydrate digestion is __________.
- monosaccharides
- polysaccharides
- glycogen
- starch
- disaccharides
monosaccharides
Rationale: With the exception of fatty acids, all macromolecules are broken down to their monomers, such as when enzymes hydrolyze complex carbohydrates into monosaccharides.
Which of the following cells produce HCl?
- parietal cells
- enteroendocrine cells
- mucous cells
- G cells
- chief cells
parietal cells
Rationale: Parietal cells make HCl and intrinsic factor.
Which of the following cells produce pepsinogen?
- mucous cells
- parietal cells
- chief cells
- G cells
- enteroendocrine cells
chief cells
Rationale: Pepsinogen is the inactive form of pepsin, which is produced by chief cells located in the basal region of gastric glands.
The digestive system in a cadaver is longer than in a living person because, in a cadaver, there is NO __________.
- food in the alimentary canal
- enzymatic activity
- digestion taking place
- muscle tone
muscle tone
Emulsification of which organic molecules would be most affected if the liver were severely damaged?
- nucleic acids
- lipids
- carbohydrates
- proteins
lipids
Rationale: Fat emulsification occurs by the detergent action of bile salts from the liver.
The short reflexes in the digestive system are stimulated by __________.
- higher brain centers
- the enteric nerve plexuses
- the parasympathetic division of the autonomic nervous system
- the sympathetic division of the autonomic nervous system
the enteric nerve plexuses
Which of the following statements about the mesentery is INCORRECT?
- Omenta is the special name for part of the mesentery extending from the curvatures of the stomach.
- It is composed of a layer of serous membrane fused with a layer of mucous membrane.
- It provides a route for blood vessels, lymphatics, and nerves to reach the digestive viscera.
- It holds the organs of the abdomen in place.
It is composed of a layer of serous membrane fused with a layer of mucous membrane.
Rationale: The mesentery is composed of two layers of serous membranes fused together.
Which of the following is the most common cause of peritonitis?
- a burst appendix
- a perforating abdominal wound
- a ruptured pancreatic cyst
- a perforating ulcer of the stomach
a burst appendix
The myxovirus causes __________.
- irritable bowel syndrome
- mumps
- infectious mononucleosis
- measles
mumps
Halitosis is caused by __________.
- increased anaerobic bacterial activity at the back of the tongue
- increased salivation
- loss of teeth
- lack of amylase in saliva
increased anaerobic bacterial activity at the back of the tongue
Which of the following teeth are most commonly impacted?
- premolars
- incisors
- wisdom teeth
- deciduous teeth
wisdom teeth
Which of the following conditions is directly associated with an increased risk for heart disease and stroke?
- periodontitis
- dental caries
- gingivitis
- impacted wisdom teeth
periodontitis
The only stomach function that is essential to life is __________.
- the presence of HCl
- the secretion of pepsinogen
- the secretion of intrinsic factor
- mechanical digestion
the secretion of intrinsic factor
Some aspects of the __________ phase of gastric secretion, which occur before food enters the stomach, may be considered conditioned reflexes.
- esophageal
- cephalic
- gastric
- intestinal
cephalic
The myenteric nerve plexus is located in which tunic of the alimentary canal?
- mucosa
- muscularis externa
- submucosa
- serosa
muscularis externa
Rationale: The myenteric nerve plexus lies between the circular and longitudinal muscle layers of the GI tract wall and controls motility.
Which of the following is a function of the gallbladder?
- storing and concentrating bile
- secreting pancreatic juice
- converting pepsinogen to pepsin
- metabolizing carbohydrate
storing and concentrating bile
Rationale: Bile that is not immediately needed for digestion is concentrated and stored by the gallbladder.
Many of the early food allergies seen in infants are caused by __________.
- lactase deficiency
- excessive absorption of fat
- gallstones
- absorption of whole proteins
absorption of whole proteins
Rationale: Absorption of whole proteins, which stimulates an immune response, is the cause of many early-life food allergies.
Which of the following is a condition affecting the large intestine that is NOT explained by anatomical or biochemical abnormalities?
- celiac disease
- pernicious anemia
- irritable bowel syndrome
- a hiatal hernia
irritable bowel syndrome
Rationale: Irritable bowel syndrome is not explained by anatomical or biochemical abnormalities and stress management is an important aspect of treatment.
