quiz - week 11 Flashcards
Which of the following statements is FALSE regarding activation and inactivation of proteolytic enzymes?
Question 1 Answer
a.
Trypsin is not needed for the activation of pepsinogen to pepsin
b.
Trypsin is not needed for the activation of brush-border peptidases
c.
Enterokinase activates trypsin when food is in the lumen of the intestine, and inactivates trypsin when food is absent
d.
Trypsin plays a key role in activating other pancreatic enzymes such as chymotrypsin and elastase
c.
Enterokinase activates trypsin when food is in the lumen of the intestine, and inactivates trypsin when food is absent
Choose the TRUE statement about the physiology of peptide YY
Question 2 Answer
a.
Peptide YY stimulates the migrating motility complex (MMC)
b.
Peptide YY is strongly stimulated by the presence of acid in the lumen
c.
Peptide YY is secreted by I cells
d.
Peptide YY is mostly secreted by cells in the distal small intestine
d.
Peptide YY is mostly secreted by cells in the distal small intestine
Choose the TRUE statement regarding the chemical digestion of fats:
Question 3 Answer
a.
Pancreatic lipase digests triglycerides, not phospholipids or cholesterol esters
b.
Pancreatic colipase is needed to activate lipase during the digestion of triglycerides within chylomicrons
c.
Lacteals carry chylomicrons from the lacteal to the hepatic portal circulation
d.
Bile contains enzymes that both emulsify fats and hydrolyze cholesterol esters
a.
Pancreatic lipase digests triglycerides, not phospholipids or cholesterol esters
Choose the TRUE statement regarding CCK physiology in the GI tract.
Question 4 Answer
a.
CCK release increases gastric emptying in order to increase digestion in the lumen of the duodenum
b.
CCK release is strongly stimulated by fats that are present in the duodenum
c.
CCK is secreted by K cells
d.
CCK is mostly secreted by cells in the duodenum
b.
CCK release is strongly stimulated by fats that are present in the duodenum
Which of the following is true regarding pepsinogen?
Question 5 Answer
a.
Pepsinogen is cleaved to active pepsin by pepsinogen kinase.
b.
Pepsin functions best at a high pH.
c.
Pepsinogen is secreted via exocytosis from chief cells.
d.
Histamine stimulates pepsinogen secretion.
c.
Pepsinogen is secreted via exocytosis from chief cells.
Which of the following is TRUE regarding stomach motility?
Question 6 Answer
a.
Retropulsion relaxes the pyloric sphincter allowing food to enter into the duodenum.
b.
Contractions of the stomach get weaker as food is pushed towards the pyloric antrum.
c.
Active dilation of the stomach to accommodate more food is called receptive relaxation.
d.
Propulsion moves food from the fundus of the stomach to the pyloric antrum.
d.
Propulsion moves food from the fundus of the stomach to the pyloric antrum.
Choose the TRUE statement regarding the function of M, or microfold, cells.
Question 7 Answer
a.
They secrete IgA produced by plasma cells into the lumen of the gut
b.
They produce large quantities of AMPs, like REG3 and lysozyme
c.
They produce a specialized type of mucous that helps concentrate IgA and AMPs at the epithelial surface
d.
They capture and transfer antigen from the gut lumen to underlying immune cells
d.
They capture and transfer antigen from the gut lumen to underlying immune cells
Which of the following messengers are important in inducing IgA class switching by intestinal B cells?
Question 8 Answer
a.
Retinoic acid
b.
Interleukin 6
c.
REG3
d.
Interleukin 4
a.
Retinoic acid
Choose the TRUE statement regarding the pathogenesis of celiac disease.
Question 9 Answer
a.
People with celiac disease increase the production of zonulin when exposed to gluten
b.
HLA-DQ2 or HLA-DQ8 are protective against the development of celiac disease
c.
APC is degraded more quickly in people with celiac disease when exposed to gluten
d.
People with celiac disease develop elongated, hypertrophic villi when exposed chronically to gluten
a.
People with celiac disease increase the production of zonulin when exposed to gluten
A 22-year-old woman presents to your clinic with fatigue and bloating that has gotten worse over the last 2 years - her family physician sent her for labwork and she had high titres (levels) of IgA against tissue transglutaminase. Which of the following statements are TRUE?
Question 10 Answer
a.
This person likely does not have celiac disease - antibody testing for food allergens like tissue transglutaminase are poorly sensitive and specific
b.
This person likely has celiac disease - further labwork should include testing for B12 and iron deficiency
c.
She needs an urgent endoscopy since small intestinal lymphoma is common in those with celiac disease
d.
This person likely does not have celiac disease - celiac disease should be obvious from childhood, the symptoms have not been present for long enough.
b.
This person likely has celiac disease - further labwork should include testing for B12 and iron deficiency
H. pylori infection of which portion of the GI tract is most commonly associated with gastric atrophy?
Question 11 Answer
a.
Stomach body
b.
Stomach cardia
c.
Stomach antrum
d.
Duodenum
a.
Stomach body
How does NSAID toxicity contribute to acute gastritis?
Question 12 Answer
a.
NSAIDS cause direct cellular damage to the gastric epithelium.
b.
NSAIDS stimulate gastrin secretion.
c.
NSAIDS inhibit prostaglandin secretion.
d.
NSAIDS stimulate histamine secretion
c.
NSAIDS inhibit prostaglandin secretion.
