Which of the following is correct?

1. The digestive system includes a tube that extends from the mouth to the anus.
2. The digestive system includes organs that food does not actually enter.
3. The digestive system shares some structures with the respiratory system.
4. A and B are correct.
5. A, B and C are correct.

E

Which of the following is NOT part of the alimentary canal?

1. tongue
2. pharynx
3. esophagus
4. stomach
5. small intestine

A

Which of the following is NOT an accessory organ of digestion?

1. a tooth
2. the appendix
3. the liver
4. the gall bladder
5. the pancreas

B

Hydrolysis of large biological molecules into smaller ones that can be absorbed by cells is

1. ingestion
2. mechanical digestion
3. chemical digestion
4. secretion
5. propulsion

C

The mucosa of the alimentary canal

1. is composed of 3 layers: epithelium, the lamina propria and the muscularis mucosae.
2. lines the lumen of the alimentary canal.
3. includes an inner sheet of circular muscle fibers and an outer layer of longitudinal fibers.
4. A and B are correct.
5. A, B and C are correct.

D

The enteric nervous system

1. controls GI tract motility via the myenteric plexus.
2. controls GI tract secretions via the submucosal plexus.
3. contains interneurons that coordinate secretions and motility.
4. A and B are correct.
5. A, B and C are correct.

E

The autonomic nervous system

1. can regulate the enteric nervous system.
2. sends sympathetic impulses to the GI tract via the vagus nerve.
3. sends parasympathetic impulses to the GI tract via nerves originating in thoracic spinal cord.
4. A and B are correct.
5. A, B and C are correct.

A

During abdominal surgery, immobilization of the patient’s intestines is often desirable. Which of the following types of medications would be most effective at immobilizing the intestines?

1. a cholinergic medication
2. an anticholinergic medication
3. an antiadrenergic medication
4. Both A and C are correct.
5. Both B and C are correct.

B

The peritoneum

1. includes the visceral peritoneum, which lines the abdominal wall.
2. includes the parietal peritoneum, which forms the serosa of GI tract organs.
3. is the largest serous membrane in the body.
4. covers the posterior side of retroperitoneal organs.
5. All of these are correct.

C

Which of the following correctly describes the oral cavity?

1. Its boundaries include the lips, the cheeks, the palate, and tongue.
2. It is part of the alimentary canal.
3. It contributes to physical (mechanical) digestion, but not to chemical digestion.
4. A and B are correct.
5. A, B and C are correct.

D

Saliva

1. is largely secreted by the parotid, sublingual and submandibular glands.
2. rich in amylase comes primarily from the parotid and submandibular glands.
3. helps moisten food so that it can be swallowed.
4. contains primarily water.
5. All of these are correct.

E

The tongue

1. forms the roof of the mouth and is covered by a serous membrane.
2. secretes lingual amylase.
3. contains intrinsic muscles used in speaking and swallowing.
4. contains taste buds in papillae on its ventral and medial surfaces.
5. All of these are correct.

C

Which of the following statements about a tooth is NOT correct?

1. The pulp cavity of a tooth is avascular, but is highly innervated.
2. The majority of an individual tooth is composed of a substance called dentin.
3. The enamel on the outer surface of a tooth is harder and more resistant to acid than bone.
4. The periodontal ligament anchors a tooth in position.
5. Root canals are extensions of the pulp cavity that run through the root of the tooth.

A

The remains of a human child are found. There are some deciduous teeth in the jaws, but permanent incisors and 1st molars are clearly present and show some wear. Second molars are barely visible, but show no wear. Based on this evidence, the age of the child at the time of death

1. can be estimated as less than 5 years of age.
2. can be estimated as older than 6 years but less than 12 years of age.
3. can be estimated as older than 12 years but less than 16 years of age.
4. can be estimated as older than 16 years but less than 20 years of age.
5. cannot be estimated.

B

A lab group is sent to the cafeteria to do an experiment. The instructions direct each student to obtain a regular saltine cracker and to chew it 25 times before swallowing. The students are to observe and record the initial and final tastes of the cracker. Most students record that the cracker initially tastes salty, but then tastes sweet. Which of the following correctly explains the students’ observations?

1. The salt on the crackers dissolved rapidly in saliva and was quickly detected by taste buds.
2. Salivary amylase digested the cracker’s starch into sugars that could be then be tasted.
3. Lingual lipase digested the cracker’s fat into sugars that could then be tasted.
4. A and B are correct.
5. A and C are correct.

D

The pharynx

1. extends from the internal nares to the esophagus.
2. is composed of smooth muscle.
3. is lined with a serous membrane.
4. serves the respiratory, but not the digestive, system.
5. All of these are correct.

A

The esophagus

1. extends from the inferior end of the pharynx to the stomach
2. contains skeletal muscle near the pharynx and smooth muscle near the stomach.
3. is lined by a mucous membrane and covered by an adventitia.
4. A and B are correct.
5. A, B and C are correct.

E

About 1/4000 babies are born with esophageal atresia, a condition in which the esophagus does not connect to the stomach. Many of these infants also have a fistula, or opening, that connects the esophagus to the trachea. How will esophageal atresia with tracheosesophageal fistula affect an infant?

1. The infant will not be able to pass milk to its stomach.
2. The infant will not be able to absorb nutrients from milk.
3. The infant may develop pneumonia from milk entering the lungs.
4. A and B are correct.
5. A, B and C are correct.

E

Deglutition

1. involves the mouth, pharynx and esophagus.
2. occurs in voluntary, pharyngeal and esophageal stages.
3. is controlled directly by the medulla oblongata and the hypothalamus.
4. A and B are correct.
5. A, B and C are correct.

D

Which of the following is NOT associated with the pharyngeal stage of deglutition?

1. A bolus is transferred from the oral cavity to the pharynx.
2. The uvula and soft palate elevate, blocking the bolus from entering the nasopharynx.
3. The epiglottis opens, allowing the bolus to enter the larynx.
4. Involuntary muscle contraction occurs.
5. The deglutition center of the brain stem is stimulated.

C

Which of the following is NOT a function of the stomach?

1. serves as the primary absorption site for most nutrients
2. receives the bolus from esophagus
3. delivers chyme to the duodenum
4. performs both mechanical and chemical digestive processes
5. produces HCl, pepsinogen and gastric lipase

A

The exit of the stomach, which is sometimes stenosed in infants, is the

1. cardia
2. pylorus
3. fundus
4. body
5. ruga

B

An individual suffering from hyposecretion by gastric chief cells would have

1. inadequate amounts of intrinsic factor and HCl.
2. excessive amounts of intrinsic factor and HCl.
3. inadequate amounts of pepsinogen and gastric lipase.
4. excessive amounts of pepsinogen and gastric lipase.
5. inadequate amounts of mucus.

C

Which of the following is NOT correct?

1. Food may remain in the gastric fundus for an hour without mixing with gastric juice.
2. 2-4 peristaltic mixing waves pass through the stomach wall each minute.
3. Salivary amylase is inactivated by the low pH of gastric juice.
4. Lingual lipase is inactivated by the low pH of gastric juice.
5. The pyloric sphincter allows small volumes of chyme to enter the duodenum.

D

HCl production

1. depends on the H⁺/K⁺ ATPase pumps in the plasma membranes of parietal cells.
2. is accompanied by increased release of HCO₃ ^- into the interstitial fluid.
3. is stimulated by ACh, gastrin and histamine.
4. A and B are correct.
5. A, B and C are correct.

E

Why doesn’t gastric juice digest the stomach?

1. The stomach is protected by an alkaline mucous membrane.
2. The proteolytic enzyme produced by the stomach is secreted in inactive form.
3. The gastric juice is too dilute to attack the stomach wall.
4. A and B are correct.
5. A, B and C are correct.

D

Which of the following is NOT absorbed by the gastric epithelium?

1. glucose
2. water
3. some ions
4. alcohol
5. short chain fatty acids

A

The pancreas

1. is anterior to the liver and stomach.
2. consists of 99% endocrine tissue and 1% exocrine tissue.
3. passes pancreatic juice to the duodenum via the pancreatic duct and hepatopancreatic ampulla.
4. A and B are correct.
5. A, B and C are correct.

C

Pancreatic juice includes all of the following EXCEPT:

1. amylase
2. HCl
3. HCO₃ ^-
4. trypsinogen
5. ribonuclease

B

Which enzyme cannot be converted to its active form without the action of enterokinase?

1. trypsinogen
2. chymotrypsinogen
3. procarboxypeptidase
4. proelastase
5. None of the enzymes listed can be activated without the action of enterokinase.

E

The sodium bicarbonate in pancreatic juice elevates the pH of chyme, which

1. blocks the action of pepsin.
2. creates favorable conditions for the actions of intestinal enzymes.
3. lowers the pH of chyme.
4. A and B are correct.
5. A, B and C are correct.

D

The liver

1. is the smallest organ inside the body.
2. is largely avascular.
3. makes bile.
4. is usually located in the left hypochondriac region.
5. is completely retroperitoneal.

C

The gallbladder

1. lies on the lateral surface of the liver.
2. concentrates and stores bile.
3. wall contains skeletal muscle.
4. contains hepatocytes arranged around central veins.
5. drains directly into the common hepatic duct.

B

Bile

1. has an acidic pH.
2. chemically digests fats.
3. contains water, bile salts, bile pigments, bile acids, cholesterol, lecithin and ions.
4. A and B are correct.
5. A, B and C are correct.

C

Hepatocytes do each of the following EXCEPT:

1. destroy worn-out blood cells and bacteria in the venous blood drained from the GI tract.
2. deaminate amino acids.
3. convert NH₃ to urea.
4. synthesize most plasma proteins.
5. convert biliverdin to hemoglobin.

E

Which of the following homeostatic disturbances might result from liver failure?

1. decreased clotting time due to increased prothrombin synthesis
2. increased bone density due to increased production of the active form of vitamin D
3. increased ability to recycle hemoglobin
4. decreased ability to maintain normal blood glucose levels
5. increased ability to convert medications and hormones into inactive substances

D

The small intestine

1. is the major site of digestion and absorption.
2. consists of the duodenum, jejunum and ileum.
3. has villi and microvilli that increase its surface area for absorption.
4. contains circular folds that increase surface area and absorption.
5. All of these are correct.

E

Which histological feature of the small intestine is correctly matched to its product?

1. Paneth cells: lysozyme
2. duodenal glands: acidic mucus
3. goblet cells: intestinal juice
4. S cells: CCK
5. K cells: secretin

A

Which substrate is correctly matched to the brush border enzymes that digest it?

1. carbohydrate: α-dextrinase, maltase, lactase, sucrase
2. protein: aminopeptidase, dipeptidase
3. nucleotide: nucleosidases, phosphatases
4. A and B are correct.
5. A, B and C are correct.

E

Which substance listed is an enzyme, but does NOT digest triglycerides?

1. bile
2. lingual lipase
3. pancreatic amylase
4. pancreatic lipase
5. gastric lipase

C

Each of the following can be absorbed across the epithelium of the small intestine EXCEPT:

1. monosaccharides
2. triglycerides
3. amino acids
4. nucleotides
5. dipeptides

B

Which substances are NOT absorbed via some form of active transport?

1. glucose
2. amino acids
3. nucleotides
4. fatty acids
5. galactose

D

Functions of the large intestine include:

1. completion of absorption
2. production of certain vitamins
3. formation of feces
4. elimination of feces
5. All of these are correct.

E

Place the following in the order in which chyme and, ultimately, feces pass through them.

1. descending colon

2. ascending colon

3. sigmoid colon

4. ileocecal valve

5. rectum

6. transverse colon

7. cecum

8. anus

1. 4, 7, 2, 6, 1, 3, 5, 8
2. 4, 7, 1, 6, 2, 3, 5, 8
3. 4, 7, 2, 1, 6, 3, 5, 8
4. 4, 7, 6, 2, 1, 3, 5, 8
5. 4, 7, 2, 6, 1, 5, 3, 8

A

Bacteria in the large intestine

1. ferment any carbohydrates left in chyme and release H₂, CO₂, and CH₄ gases.
2. convert any amino acids left in chyme into simpler substances, e.g. indole, skatole, and H₂S.
3. decompose bilirubin to simpler pigments such as stercobilin.
4. synthesize some B vitamins and vitamin K.
5. All of these are correct.

E

The cephalic stage of digestion

1. begins when food enters the stomach.
2. is regulated primarily by CCK.
3. prepares the mouth and stomach for the arrival of food.
4. A and B are correct.
5. A, B and C are correct.

C

The intestinal phase of digestion

1. begins when someone thinks about, sees, smells, initially tastes food.
2. is an immediate response to stomach distension.
3. occurs quickly after ingested food raises gastric pH.
4. is mediated by CCK and secretin.
5. All of these are correct.

D

CCK

1. is secreted by cells in the crypts of the large intestine.
2. stimulates the release of pancreatic juice rich in digestive enzymes.
3. stimulates the relaxation of the gall bladder wall.
4. increases gastric emptying.
5. produces a feeling of hunger by acting on the hypothalamus.

B

Which of the following is correct?

1. The endoderm of the primitive gut forms the epithelium of most of the digestive tract.
2. The mesoderm of the primitive gut forms the glands of most of the digestive tract.
3. The endoderm of the primitive gut forms the smooth muscle of most of the digestive tract.
4. The endoderm of the primitive gut forms the connective tissue of most of the digestive tract.
5. All of these are correct.

A

Which of the following is an expected age-related change in the digestive system?

1. decreased secretory mechanisms
2. decreased smooth muscle tone
3. decreased motility
4. A and B are correct.
5. A, B and C are correct.

E