Physio Cont.

8/3/2019 Physio Cont.

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1. A surgeon makes an incision in the

jejunum starting at the serosal surface

and ending in the lumen. What is the

sequential order of bisected structures

as the scalpel passes through the

intestinal wall?

(A) Circular muscle longitudinal

muscle submucous plexus

(B) Longitudinal muscle myenteric

plexus circular muscle

(C) Myenteric plexus circular

muscle longitudinal muscle

(D) Network of interstitial cells of

Cajal longitudinal muscle

circular muscle

(E) Longitudinal muscle network of

interstitial cells of Cajal submucous

plexus

2. A mouse with a new genetic mutation

is discovered not to have electrical

slow waves in the small intestine. What

cell type is most likely affected by the

mutation?

(A) Enteric neurons


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(B) Inhibitory motor neurons

(C) Enterochromaffin cells

(D) Interstitial cells of Cajal

(E) Enteroendocrine cells

3. A patient with chronic intestinal

pseudoobstruction has action

potentials and large- amplitude

contractions of the circular muscle

associated with every electrical slow

wave at all levels of the intestine in the

interdigestive state. Dysplasia of which

cell type most likely explains this

patients condition?

(A) Unitary-type smooth muscle

(B) Interstitial cells of Cajal

(C) Inhibitory motor neurons

(D) Sympathetic postganglionic

neurons

(E) Vagal efferent neurons

4. A neural tracer technique labels the

axon and cell body when it is applied

to any part of a neuron. Where are

labeled cell bodies most likely to be


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found after the tracer substance is

injected into the wall of the stomach?

(A) Prefrontal cortex

(B) Intermediolateral horn of spinal

cord

(C) Dorsal vagal complex

(D) Hypothalamus

(E) Gray matter of sacral spinal cord

5. An electrophysiological study of a

neuron in the ENS detects a fast EPSP.

Which is the most likely property

associated with the EPSP?

(A) Acetylcholine (ACh) receptors

(B) Suppression of hyperpolarizing

after-potentials

(C) Receptor activation of adenylyl

cyclase

(D) Hyperpolarization of the

membrane potential

(E) Mediation by a metabotropic

receptor

6. The application of norepinephrine

(NE) to the ENS suppresses


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cholinergically mediated EPSPs but has

no effect on depolarizing responses to

applied acetylcholine (ACh). This

finding is best interpreted as

(A) Postsynaptic excitation

(B) Slow synaptic inhibition

(C) Presynaptic inhibition

(D) Postsynaptic facilitation

(E) Inhibitory junction potential

7. A 10-cm segment of small intestine is

removed surgically and placed in a

37 C physiological solution containing

tetrodotoxin. A stimulus at one end of

the segment evokes an action potential

and an accompanying contraction that

travels to the opposite end of the

segment. This finding is best explained

by

(A) Electrical slow waves

(B) Varicose motor nerve fibers

(C) Interstitial cells of Cajal

(D) Functional electrical syncytial

properties

(E) Release of neurotransmitters


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8. A disease that results in the loss of

enteric inhibitory motor neurons to the

musculature of the digestive tract will

most likely be expressed as

(A) Rapid intestinal transit

(B) Accelerated gastric emptying

(C) Gastroesophageal reflux

(D) Diarrhea

(E) Achalasia of the lower esophageal

sphincter

9. The viewing of intestinal peristaltic

propulsion in real time with magnetic

resonance imaging shows the

stereotyped formation of propulsive

and receiving segments. What is the

normal sequence of events in enteric

neural programming of the propulsive

and receiving segments?

(A) Relaxation of the longitudinal and

circular muscles in the propulsive

segment

(B) Relaxation of the circular and

longitudinal muscles in the receiving


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segment

(C) Contraction of the longitudinal

and circular muscles in the receiving

segment

(D) Relaxation of the circular muscle

and contraction of the longitudinal

muscle in the receiving segment

(E) Contraction of the longitudinal

muscle and relaxation of the circular

muscle in the propulsive segment

10.Examination of the properties of a

normal sphincter in the digestive tract

will show that

(A) Primary flow across the sphincter is

unidirectional

(B) The lower esophageal sphincter is

relaxed at the onset of a migrating

motor complex in the stomach

(C) Blockade of the sphincteric

innervation by a local anesthetic causes

the sphincter to relax

(D) The manometric pressure in the

lumen of the sphincter is less than the

pressure detected in the lumen on


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either side of the sphincter

(E) The inhibitory motor neurons to

the sphincter muscle stop firing during

a swallow

11.The absence of intestinal motility in

the normal small intestine is best

described as

(A) A migrating motor complex

(B) An interdigestive state

(C) Segmentation

(D) Physiological ileus

(E) Power propulsion

12.The best description of the lag phase

of gastric emptying is the time required

for

(A) Conversion from the interdigestive

to the digestive enteric motor program

(B) Maximal stimulation of gastric

secretion

(C) Return of the emptying curve to

baseline

(D) Reduction of particle size to occur

(E) Emptying of half of a liquid meal


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13. Increased strength of the trailing

component of the contractile complex

in the gastric antral pump is most

likely to occur when

(A) Excitatory motor neurons are

activated to release ACh at the antral

musculature

(B) Sympathetic postganglionic

neurons decrease the amplitude of the

plateau phase of the gastric action

potential

(C) Frequency of the gastric action

potential increases beyond 3/min

(D) The pyloric sphincter opens

(E) Excitatory motor neurons to the

musculature of the gastric reservoir are

activated

14.When elevated in an ingested meal,

the factor with the greatest effect in

slowing gastric emptying is

(A) pH

(B) Carbohydrate

(C) Protein


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(D) Lipid

(E) H2O

15.On a return visit after receiving a

diagnosis of functional dyspepsia, a 35-

year-old woman reports sensations of

early satiety and discomfort in the

epigastric region after a meal. These

symptoms are most likely a result of

(A) Malfunction of adaptive relaxation

in the gastric reservoir

(B) Elevated frequency of contractions

in the antral pump

(C) An incompetent lower esophageal

sphincter

(D) Premature onset of the

interdigestive phase of gastric motility

(E) Bile reflux from the duodenum

16.A 46-year-old university professor with

an allergy to shellfish must be cautious

when eating in restaurants because a

trace of shrimp in any form of food

triggers an allergic reaction, including

abdominal cramping and diarrhea.


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Which kind of contractile behavior is

the most likely intestinal motility

pattern during the professors allergic

reaction to shellfish?

(A) Physiological ileus

(B) Migrating motor complex

(C) Retrograde peristaltic propulsion

(D) Segmentation

(E) Power propulsion

17.The instillation of markers in the large

intestine is used to evaluate transit time

in the large intestine and diagnose

motility disorders. In healthy subjects,

dwell-times for instilled markers in the

large intestine are greatest in the

(A) Ascending colon

(B) Sigmoid colon

(C) Descending colon

(D) Transverse colon

(E) Anorectum

18.An 86-year-old woman has complaints

of a compromised lifestyle because of

fecal incontinence. Examination of this


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patient will most likely reveal the

underlying cause of the incontinence

to be

(A) Absence of the rectoanal reflex

(B) Elevated sensitivity to the presence

of feces in the rectum

(C) Loss of the ENS in the distal large

intestine (adult Hirschsprungs disease)

(D) Weakness in the puborectalis and

external anal sphincter muscles

(E) A myopathic form of chronic

pseudoobstruction in the large

intestine

1. Most of the following GI secretions

have a basal output during the

interdigestive period (between meals).

However, the sight and smell of a tasty

meal stimulates GI secretions. Of the

various GI secretions, which is the

most stimulated?

(A) Gastric secretion

(B) Intestinal secretion

(C) Pancreatic secretion

(D) Salivary secretion


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(E) Biliary secretion

2. Bile acid uptake by hepatocytes is

dependent on

(A) Calcium

(B) Iron

(C) Sodium

(D) Potassium

(E) Chloride

3. Parietal cells in the stomach secrete a

protein crucial for the absorption of

vitamin B12 by the ileum. What is this

protein?

(A) Intrinsic factor

(B) Gastrin

(C) Somatostatin

(D) Cholecystokinin (CCK)

(E) Chylomicrons

4. Gastric acid secretion is stimulated

during several phases associated with

the ingestion and digestion of a meal.

Which phase is associated with the

bulk of acid secretion?


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(A) Cephalic

(B) Esophageal

(C) Gastric

(D) Intestinal

(E) Colonic

5 Carbonic anhydrase is an enzyme that

occurs in plants, bacteria, and animals

and is involved in the formation of

which chemical?

(A) Carbon dioxide from carbon and

oxygen

(B) Carbonic acid from carbon dioxide

and water

(C) Bicarbonate ion from carbonic acid

(D) Hydrochloric acid

(E) Hypochlorous acid

6. Parasympathetic stimulation induces

salivary acinar cells to release the

protease

(A) Bradykinin

(B) Kallikrein

(C) Kininogen

(D) Kinin


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(E) Aminopeptidase

7. Which protein is absent in saliva?

(A) Lactoferrin

(B) Amylase

(C) Mucin

(D) Intrinsic factor

(E) Muramidase

8. After the ingestion of a meal, the pH

in the stomach lumen increases in

response to the dilution and buffering

of gastric acid by the arrival of food.

The pH in the stomach lumen in the

fasting state is usually between

0.1 to 0.5

(A) 1 to 2

(B) 4 to 5

(C) 6 to 7

(D) 9 to 10

9. Unlike other GI secretions, salivary

secretion is controlled almost

exclusively by the nervous system and

is significantly inhibited by


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(A) Atropine

(B) Pilocarpine

(C) Cimetidine

(D) Aspirin

(E) Omeprazole

10.The chief cells of the stomach secrete

(A) Intrinsic factor

(B) Hydrochloric acid

(C) Pepsinogen

(D) Gastrin

(E) CCK

11.The interaction of histamine with its

H2 receptor in the parietal cell results

in

(A) An increase in intracellular sodium

concentration

(B) An increase in intracellular cAMP

production

(C) An increase in intracellular cGMP

production

(D) A decrease in intracellular calcium

concentration

(E) A decrease in intracellular cAMP


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production

12.When the pH of the stomach lumen

falls below 3, the antrum of the

stomach releases a peptide that acts

locally to inhibit gastrin release. This

peptide is

(A) Enterogastrone

(B) Intrinsic factor

(C) Secretin

(D) Somatostatin

(E) CCK

13.Which hormone stimulates pancreatic

secretion that is rich in bicarbonate?

(A) Somatostatin

(B) Secretin

(C) CCK

(D) Gastrin

(E) Insulin

14.A patient suffering from Zollinger-

Ellison syndrome would be expected to

have

(A) Excessive acid reflux into the


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esophagus, resulting in esophagitis

(B) Excessive secretion of CCK,

causing continuous contraction of the

gallbladder

(C) A gastrin-secreting tumor of the

pancreas, causing excessive stomach

acid secretion and peptic ulcers

(D) Low plasma lipid levels, due to

failure of the liver to secrete VLDLs

(E) Inadequate secretion of bicarbonate

by the pancreas

15.Lactase is a brush border enzyme

involved in the digestion of lactose.

The digestion product or products of

lactose are

(A) Glucose

(B) Glucose and galactose

(C) Glucose and fructose

(D) Galactose and fructose

(E) Fructose

16.Maltase hydrolyzes maltose to form

(A) Glucose

(B) Glucose and galactose


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(C) Glucose and fructose

(D) Galactose and fructose

(E) Galactose

17.Which sugar is taken up by

enterocytes by facilitated diffusion?

(A) Glucose

(B) Galactose

(C) Fructose

(D) Xylose

(E) Sucrose

18.Dietary triglyceride is a major source

of nutrient for the human body. It is

digested mostly in the intestinal lumen

by pancreatic lipase to release

(A) Lysophosphatidylcholine and fatty

acids

(B) Glycerol and fatty acids

(C) Diglyceride and fatty acids

(D) 2-Monoglyceride and fatty acids

(E) Lysophosphatidylcholine and

diglyceride

19.After a meal of pizza, dietary lipid is


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absorbed by the small intestine and

transported in the lymph mainly as

(A) VLDLs

(B) Free fatty acids bound to albumin

(C) Chylomicrons

(D) LDLs

(E) HDLs

20.Hartnups disease is an inherited

autosomal recessive disorder involving

the malabsorption of amino acids,

particularly tryptophan, by the small

intestine. Feeding dipeptides and

tripeptides containing tryptophan to

patients with this disease improves

their clinical condition because

(A) Dipeptides and tripeptides, unlike

free amino acids, can be taken up

passively by enterocytes in the small

intestine

(B) Peptides, unlike free amino acids,

can be taken up by defective amino

acid transporters

(C) Dipeptides and tripeptides use

transporters that are different from the


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defective amino acid transporters

(D) The presence of dipeptides and

tripeptides in the intestinal lumen

enhances the uptake of amino acids by

the transporters

(E) Dipeptides and tripeptides, unlike

amino acids, can be taken up passively

by the colon

21.What would you expect to find in a

sample of hepatic portal blood after

protein has been digested and

absorbed by the GI tract?

(A) Free amino acids

(B) Dipeptides and tripeptides

(C) Free amino acids and dipeptides

(D) Free amino acids and tripeptides

(E) Free amino acids, dipeptides, and

tripeptides

22.Which vitamin is water-soluble?

(A) Vitamin A

(B) Vitamin D

(C) Vitamin K

(D) Vitamin B1


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(E) Vitamin E

23.Which one of the following vitamins

stimulates calcium absorption by the

GI tract?

(A) Vitamin E

(B) Vitamin D

(C) Vitamin A

(D) Vitamin K

(E) Vitamin C

24.Which vitamin is transported in

chylomicrons as an ester?

(A) Vitamin E

(B) Vitamin D

(C) Vitamin A

(D) Vitamin K

(E) Vitamin B12

25.Potassium is absorbed in the jejunum

by

(A) Active transport

(B) Facilitated transport

(C) Passive transport

(D) Active and passive transport


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(E) Coupling to sodium absorption

26.Ascorbic acid is a potent enhancer of

iron absorption because it

(A) Enhances the absorption of heme

iron

(B) Enhances the activity of heme

oxygenase

(C) Is a reducing agent, thereby

helping to keep iron in the ferrous

state

(D) Decreases the production of

ferritin by enterocytes

(E) Stimulates production of

transferrin

Physio Cont.

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