GI Physiology MCQs
20th February 2007
1.
All of the following are correct statements about pancreatic exocrine secretion
EXCEPT
a.
b.
c.
d.
e.
2.
The major mechanism for absorption of sodium from the small intestine is
a.
b.
c.
d.
e.
3.
d.
e.
Bile acids are secreted as conjugated bile salts by the liver
Bile acids are dehydroxylated by intestinal bacteria
Bile acids are absorbed in the intestine and return to the liver via the
portal vein
Bile acids facilitate absorption of fat by emulsifying glycerides
Sulfation of bile acids promotes their uptake in the intestine
Dietary fat is absorbed chiefly in the
a.
b.
c.
d.
e.
5.
Non electrolytic cotransport
Cotransport with potassium
Electrogenic transport
Neutral NaCl absorption
Solvent drag
All of the following statements about bile acids are correct EXCEPT
a.
b.
c.
4.
Bicarbonate rich fluid is secreted by ductal epithelial cells in response
to secretin
Secretion of enzymes by acinar cells occurs in response to CCK
Vagotomy augments secretion of enzymes after a meal
Secretin and CCK both act via formation of cyclic nucleotide 2nd
messengers
Gastrin stimulates both enzyme and bicarbonate secretion
Stomach
Jejunum
Ileum
Caecum
Ascending colon
Gallbladder contraction is controlled primarily by the hormone
a.
b.
c.
d.
e.
Enterogastrone
CCK
Insulin
Secretin
Glucagon
6.
All of the following statements about somatostatin are true EXCEPT
a.
b.
c.
d.
e.
7.
Compared with the resting state – during prolonged exercise the caloric
needs of skeletal muscle are met by
a.
b.
c.
d.
e.
8.
d.
e.
Subsequent to its cleavage from proinsulin in the  cell
A response to both vagal and  adrenergic stimulation
The stimulator of release of pancreatic enzymes in response to
glucose
Inhibited by exercise
None of the above
Activation of hormone sensitive lipase in adipocytes
a.
b.
c.
d.
e.
11.
Reversible hydrophobic interactions
Allosteric regulation
Hydrogen bonding
Formation of covalent linkages
Coupling with an activity site
Secretion of pancreatic polypeptide is
a.
b.
c.
10.
Release of free fatty acids from adipose tissue
An increase in hepatic glycogenolysis
An increase in gluconeogenesis in muscle
Increased intestinal uptake of glucose and amino acids
None of the above
Binding of a peptide hormone to its receptor may involve all of the following
EXCEPT
a.
b.
c.
d.
e.
9.
It inhibits gastrin secretion
It is secreted by the hypothalamus
It is secreted by pancreatic islet cells
It is released following vagal blockade
Its effects are prolonged
Causes increased hydrolysis of cholesterol esters
Is mediated by a cAMP dependent protein kinase
Is prevented by cortisol
Is stimulated by insulin
Results in accumulation of monoglycerides and diglycerides in
adipocytes
All of the following statements about the uptake of triglycerides into adipose
tissue from plasma lipoproteins are true EXCEPT
a.
b.
c.
d.
e.
It
It
It
It
It
is regulated by the activity of lipoprotein lipase
is decreased by catecholamines
is increased by glucose
is increased by insulin
requires receptor mediated endocytosis
12.
The islets of Langerhans are characterised by
a.
b.
c.
d.
e.
13.
Dietary fat, after being processes, is extruded from the mucosal cells of the
GI tract into the lymphatic ducts in the form of
a.
b.
c.
d.
e.
14.
CO2 liberated by the interaction of HCO3- and H+
Diffusion from the blood
Fermentation of undigested oligo saccharides by bacteria
Swallowed atmospheric air
None of the above
Vitamins synthesised by intestinal bacteria and absorbed in significant
quantities include
a.
b.
c.
d.
e.
17.
Carbohydrate in gastric contents
Secretion of gastrin by antral G cells
Distension of the duodenum
Osmolarity of duodenal contents
Acidity of chime entering the duodenum
Gas within the colon is primarily derived from which one of the following
sources
a.
b.
c.
d.
e.
16.
Monoglycerides
Diglycerides
Triglycerides
Chylomicrons
Free fatty acids
The rate of gastric emptying is influenced by all of the following factors
EXCEPT
a.
b.
c.
d.
e.
15.
Being more plentiful in the head of the pancreas than in the tail
Constituting 20 – 30% of the weight of the pancreas
Containing at least 6 distinct cell types
Having a meagre blood supply
Producing glucagon and insulin
Vitamin B6
Vitamin K
Thiamine
Riboflavin
Folic acid
Which one of the following statements about the colon is correct
a.
b.
c.
d.
e.
Absorption of Na+ in the colon is under hormonal (aldosterone) control
Bile acids enhance absorption of water from the colon
Net absorption of HCO3- occurs in the colon
Net absorption of K+ occurs in the colon
The luminal potential in the colon is positive
18.
Absorption of fat soluble vitamins requires
a.
b.
c.
d.
e.
19.
Contraction of the gallbladder is correctly described by which one of the
following statements
a.
b.
c.
d.
e.
20.
CCK
Gastrin
Histamine
Secretin
None of the above
Decrease pancreatic secretion of bicarbonate
Increase secretion of gastric acid
Decrease gastric emptying
Increase contraction of the gallbladder
Increase contraction of the sphincter of oddi
In contrast to secondary oesophageal peristalsis, primary oesophageal
peristalsis is characterised by which of the following statements
a.
b.
c.
d.
e.
23.
is inhibited by a fat rich meal
is inhibited by the presence of amino acids in the duodenum
is stimulated by atropine
occurs in response to CCK
occurs simultaneously with the contraction of the sphincter of oddi
Acidification of the duodenum will
a.
b.
c.
d.
e.
22.
It
It
It
It
It
Which of the following is a paracrine secretion
a.
b.
c.
d.
e.
21.
Intrinsic factor
Chymotrypsin
Pancreatic lipase
Pancreatic amylase
None of the above
It does not involve relaxation of the lower oesophageal sphincter
It involves contraction of oesophageal smooth muscle
It is not influenced by the intrinsic nervous system
It has an oropharyngeal phase
None of the above
The stimulation of release of pancreatic secretions normally involves all of the
following EXCEPT
a.
b.
c.
d.
e.
Ach
CCK
Histamine
Neural stimulation
Secretion
24.
Intestinal proteolysis is accomplished by all of the following EXCEPT
a.
b.
c.
d.
e.
25.
The concept that active transport is the mechanism for absorption of
monosaccharides in the gut is supported by all of the following statements
EXCEPT
a.
b.
c.
d.
e.
26.
d.
e.
Its pH is approximately 8.0
It has a high bicarbonate content
Over 1000ml are secreted per day
It contains cholesterol esterase
Its secretion is primarily under neural control
Mass movements (strong peristalsis) in the colon would be abolished by
a.
b.
c.
d.
e.
29.
A decrease in absorption of amino acids
An increase in the water content of the faeces
An increase in the concentration of bile acid in the enterohepatic
circulation
A decrease in the fat content of the faeces
An increase in the absorption of iron
All of the following statements concerning normal human pancreatic juice are
true EXCEPT
a.
b.
c.
d.
e.
28.
Transport can be blocked by metabolic inhibitors
Transport is selective for different sugars
A maximum rate of transport exists for individual monosaccharides
Competition exists among sugars for the carrier mechanism
Transport can occur bidirectionally
Removal of the terminal ileum will result in
a.
b.
c.
27.
Carboxypeptidase
Chymotrypsin
Elastase
Pepsin
Trypsin
Vagotomy
Extrinsic denervation
Distension of the colon
Destruction of Meissner’s plexus
Destruction of Auerbach’s plexus
Saliva has all the following constituents EXCEPT
a.
b.
c.
d.
e.
Bicarbonate
Phosphate
Chloride
Glucose
Lysozyme
30.
Where are vitamins A, D and K absorbed
a.
b.
c.
d.
e.
31.
Regarding carbohydrate metabolism – which of the following statements is
correct
a.
b.
c.
d.
e.
32.
is relatively higher in women than men
falls about 10% during sleep
is increased by tension
falls about 40% during prolonged fasting
increases in high and low environmental temperatures
Calcium
Luminal peptides and amino acids
Secretin
Epinephrine
Increased vagal discharge
Regarding GI hormones
a.
b.
c.
d.
e.
35.
It
It
It
It
It
All of the following increase gastrin secretion EXCEPT
a.
b.
c.
d.
e.
34.
About 80% of energy supplies are stored in fat
Most of the glycogen stores are in the liver
Resting muscle utilises glucose for its metabolism
At rest – the brain accounts for 40 – 50% of glucose utilised
5% of ingested glucose is promptly converted to fat
Regarding basal metabolic rate – all are true EXCEPT
a.
b.
c.
d.
e.
33.
Stomach
Proximal small bowel
Terminal ileum
Duodenum
Ascending colon
Luminal somatostatin inhibits gastrin secretion
CCK secretion is increased by the presence in the duodenum of fatty
acids containing more than 3 carbon atoms
GIP is produced by the ileum
Secretin increases the section of an enzyme rich pancreatic juice
VIP causes contraction of intestinal smooth muscle
Regarding the principal lipoproteins
a.
b.
c.
d.
e.
Chylomicrons originate in the liver
IDLs are 40% phospholipids
LDLs are 20nm in size
HDLs are 25% protein
VLDLs are 6% triglyceride
GI Physiology MCQs
21st February 2006
Answers
1.
C
32.
A
2.
D
33.
C
3.
E
34.
A
4.
B
35.
C
5.
B
6.
E
7.
B
8.
D
9.
B
10.
B
11.
E
12.
E
13.
D
14.
A
15.
C
16.
E
17.
A
18.
C
19.
D
20.
C
21.
C
22.
D
23.
C
24.
D
25.
E
26.
B
27.
E
28.
E
29.
D
30.
B
31.
A