GI Past papers – edited by Dr. Mohammad Alamer:
1. Blood flow toward gastrointestinal tract is controlled by all of the following, except:
a. ICC (interstitial cells of cajal)
b. ENS
c. ANS
d. VIP
e. All of the above control blood flow to the GI
Answer is (a)
2. All of the following may describe the contraction that appear along the small intestine except:
a. Segmentation contractions decrease in frequency as we move from duodenum towards
ileum and they are controlled by the BER
b. Peristaltic rush is a response to mucosal irritation
c. MMC happens between meals and the contractions increase gradually
d. Increased velocity of chyme propulsion may lead to an increased intestinal absorption
e. Movement of Muscularis mucosae allows the mucosal folds to change their shape
Answer is (d)
3. One of the following with regard to contractions that appear in the colon is not true:
a. Mass contraction are present throughout the day in the colon
b. Haustration contractions are responsible for moving feces into the transverse colon
c. Haustration contractions involve contraction in both muscle layers of the Muscularis
d. Mass contractions are stimulated by filling of the stomach and the duodenum
e. All of the above is true
Answer is (a)
4. One of the following describes pepsinogens:
a. Mainly Secreted by chief cells
b. More active in media with low pH
c. It is a lipolytic enzyme
d. It functions in the stomach and the small intestines
e. More than one of the above
Answer is (e) a and b are correct
5. Gastric HCl secretions is increased by all of the following except:
a. Histamine
b. Filling of the stomach
c. Thinking about and smelling food through vagal reflexes
d. Presence of Proteins in the stomach through gastrin
e. Activation of enterogastric reflex
Answer is (e). this reflex inhibits gastric secretions
6. One of the following concerning pancreatic secretion is not true:
a. The enzymatic secretion is stimulated by CCK
b. HCO3- secretion is stimulated by Secretin
c. HCO3- is decreased at high rate of secretion
d. Cl- is decreased at high rate of secretion
e. The proteolytic enzymes are inactive in the pancreas
Answer is (c) because it is actually increased at high rates of secretion
7. One of the following about digestion of protein is true:
a. Some of the digestion processes are carried out by brush border & cytosomal
peptidases
b. Protein digestion begins in the oral cavity
c. In the stomach, initially there is no protein digestion in the peripheral part of the food
mass
d. Most protein digestion takes place in the ileum
e. More than one of the above
Answer is (a)
8. One of the followings with regard to fat absorption is true:
a. Fat is absorbed directly into the capillaries
b. Fat absorption requires brush border enzymes
c. Most lipids we consume are in the form of cholesterol
d. Fat absorption happens by secondary active cotransport with Na+
e. None of the above
Answer is (e)
9. By blocking the activity of Na+/K+ pump at absorptive cells, this will affect the absorption of:
a. Water
b. Na+
c. Amino acids
d. Glucose
e. All of the above
Answer is (e)
10. With regard the absorption of vitamins, one of the following is not true:
a. Vitamin B12 is absorbed in the terminal ileum and requires the presence of intrinsic
factor
b. Vitamin A is absorbed by facilitated diffusion
c. Vitamin D is absorbed by simple diffusion
d. Vitamin B1 requires active transport
e. More than one of the above
Answer is (b)
11. All of the following with regard to RQ are true except:
a. Is affected by the type of food the person consumes
b. When the source of food is glucose it will equal 1
c. It is decreased when the source of food is protein instead of glucose
d. Increased by decreasing the ratio of CO2 production / O2 consumption
e. More than one of the above
Answer is (d)
12. In normal person, feeding can be stimulated by increasing:
a. Leptin
b. Glucose and insulin in the blood
c. Body metabolic rate
d. Going to moderate climate areas instead of cold areas
e. All of the above
Answer is (c)
13. One of the following about starvation is true:
a. The first source of energy to be depleted is lipids
b. Glycogen stores are sufficient for 4 days
c. Depletion of proteins appear in 3 phases
d. When proteins are depleted, the person is still functional and healthy and can survive
for weeks afterwards
e. More than one of the above
Answer is (c)
14. One of the following about salivary gland secretion is true:
a. Decreased by conditioned reflexes
b. The amount of Na+ and Cl- in the final secretions is higher than plasma
c. At high flow rates, the amount of HCO3- will decrease
d. Increases by unconditioned reflexes
e. More than one of the above
Answer is (d)
15. About swallowing, all true except:
a. Composed of voluntary and involuntary phases.
b. Primary peristalsis is initiated at the pharynx
c. Secondary peristalsis is initiated in the esophagus by remnants of food in the esophagus.
d. Preceded by relaxation wave to open the lower esophageal sphincter.
e. Closure of epiglottis is voluntary.
Answer is (e), it is part of the pharyngeal involuntary phase.
16. The wrong statement about pepsin
a. Pepsin is activated by high pH
b. Pepsin is a proteolytic enzyme
c. It is released by chief cells of the stomach
d. Pepsin production is increased by the presence of proteins in the stomach
e. All of the above are wrong
Answer is (a)
17. Which of the following produce the highest metabolic rate:
a. Sleep
b. Hypothyroidism
c. Basal state
d. Fever
e. Malnutrition
Answer is (d)
18. Which of the following is true about protein digestion:
a. Digestion of protein is initiated at the mouth.
b. Pepsin is secreted in its active form
c. Pepsin is inactivated in duodenum by enterokinases
d. Digestion is continued by brush border enzymes, and intracellular enzymes.
e. More than one of the above
Answer is (d)
19. About pancreatic secretion, all true except:
a. CCK increase enzymatic production.
b. HCO3 and water production is increases by secretin
c. Controlled by parasympathetic system
d. Affected by blood flow to pancreas.
e. Decease HCO3 concentration during active secretion.
Answer is (e)
20. Which of the following decreases gastric emptying:
a. Distention of the stomach
b. Activation of Pyloric Pump
c. High fat content in chyme in the duodenum
d. Activation of G-cells in the pylorus
e. More than one of the above
Answer is C (that will release CCK which will inhibit gastric emptying. Moreover, the
enterogastric reflex will further inhibit gastric emptying). A/b/d all of them will stimulate
gastric emptying (refer to handout 1 page 11)
21. Which of the following about carbohydrates is correct:
a. All monosaccharides require a carrier for absorption
b. They are all absorbed in the form of disaccharides
c. Glucose and galactose are absorbed by facilitated diffusion
d. Dextrose form is absorbable
e. More than one of the above
Answer : e. because (a) is correct (the carrier can be for secondary active transport in
the case of glucose and galactose and for facilitated diffusion in the case of fructose)
and (d) is correct. B and c are both wrong.
22. If we inhibit the Na+/K+ pump, the absorption of which of the following will be affected:
a. Water
b. Fatty acids
c. Vitamin a
d. Fructose
e. More than one of the above
Answer is (a) because the others are absorbed passively (fatty acids and vit-a by simple
diffusion and fructose by facilitated diffusion).
23. Which of the following about bile is correct:
a. It acts as a detergent
b. Bile salts act to emulsify fat
c. It forms micelles in the small intestines
d. All bile Is lost in feces and resynthesized de novo in the liver
e. More than one of the above
Answer: (e). although d is wrong, all the other answers are correct
24. Which of the following is correct about pancreatic secretions
a. All proteases are endopeptidases
b. Decreased pancreatic secretions results in steatorrhea
c. It is inhibited by CCK and Secretin
d. It is only regulated locally by hormones with no role for neural regulation
e. More than one of the above
Answer: D. remember that steatorrhea is fatty stool. Without pancreatic enzymes fat is
not digested and therefore not absorbed and will remain in stool. The other answers are
all wrong as the proteases are endo and exo peptidases, CCK and Secretin increase
secretions, and the regulation is done by both local and neural mechanisms in 3 phases.
25. Which of the following is NOT true about RQ (respiratory quotient):
a. It is highest for carbohydrates
b. It is lower for lipids
c. It can be decreased by decreasing the ratio of CO2 production/O2 consumption
d. It is highest in the brain
e. It is high during the 3rd week of starvation
Answer: (e). you should know that (a), (b) and (c) are correct. As for (d) you should also
know from biochemistry that the brain depends almost entirely on the metabolism of
carbohydrates for energy which makes the RQ high in the brain. (e) is wrong because
during the 3rd week of starvation the source of energy for the body is by using the stores
of fat for energy (as opposed to the first few hours when the body uses carbohydrates)
26. Which of the following doesn’t result in obesity:
a. Over production of Leptin from adipocytes
b. A defect in the OB gene
c. Childhood over nutrition
d. A defect in the feeding and satiety centers in the hypothalamus
e. Positive energy balance
Answer: (a) because leptin is the satiety hormone. All the others are obvious causes of
obesity.
27. The lowest RQ:
a. After 2 hours of starvation
b. After 3 weeks of starvation
c. After glucose intake
d. When the source of energy is a mixture of all foods
e. RQ is always constant and only changed by the function of the respiratory system
Answer is (b) because the source will be almost exclusively lipids.
28. Which of the following might happen in pancreatic insufficiency?
a. Steatorrhea
b. Vitamin K deficiency
c. Increased synthesis of chylomicrons
d. Increased absorption of lipids
e. More than one of the above
Answer: (e) because both a and b are correct. Remember than vitamin K is lipid soluble
and requires the same mechanisms as lipids for absorption.
29. The lowest O2 consumption by the tissues:
a. After exercise
b. Sleeping with basal conditions
c. All basal conditions
d. Hyperthyroidism
e. Cold weather
Answer: (b). during sleep O2 consumption is decreased as all the metabolic activities are
decreased than from the normal basal conditions while awake. The other answers are
things that would increase the BMR and O2 consumption.
30. When there are food remnants in the esophagus that will initiate:
a. Primary peristalsis
b. Secondary peristalsis
c. MMC
d. Pyloric Pump
e. Mass Contractions
Answer: (b)
31. Concerning Leptin, which of the following is wrong:
a. Secreted from adipocytes
b. Increased secretion when adipocytes are filled with lipids
c. Reaches the hypothalamus and increases appetite
d. More than one of the above
Answer: (c). it actually goes to the hypothalamus and decreases appetite and causes
satiety.
32. Correct about pancreatic proteolytic enzymes:
a. Secreted from acinar cells
b. Plays a role in glucose homeostasis
c. Secreted in the active form
d. For activation of the enzymes chemotrypsin is the most important one
e. More than one of the above
Answer: (a). it has nothing to do with glucose. It is secreted as inactive, and for
activation trypsin is the most important one.