Digestive System Revision

Where are most gastric acid-secreting cells (parietal cells) located?

• Small intestine

• Gastric pit in the fundus

• Oesophagus

• Majority of the stomach lining

Extracellular signals such as _______ can activate acid secretion from parietal cells. Give one example.

Stomach epithelial cells (aka mucous cells) are only found in the gastric pit.

• True

• False

• Probably...

H⁺ and bicarbonate are produced from water and carbon dioxide by the action of ______ within the parietal cell. (Hint: an enzyme)

H2 receptor antagonist prevents binding of the natural ligand. What is the natural ligand of H2 receptor?

• His amine

• Ranitidine

• Histamine

• Acetylcholine

Which ONE of the statement below is true?

• Proton pump is locked in E2 state by PPI.

• E1 state has low affinity for H+.

• K+ enters into the cells using energy derived from the concentration gradient of H+.

Which ONE of the statements below regarding H. pylori is correct?

• Urease is secreted into the stomach lumen by H. pylori.

• Urea channel in H. pylori is located in the outer membrane.

• Urea channel will open when pH < 5.

• Urea breath test detects the urea produced H. pylori.

Which diagnostic test(s) below detects H. pylori by antigen-antibody interaction? There can be more than one correct answer.

• Blood test (ELISA)

• Stool test (test strip)

• Urea breath test

• Biopsy and CLO test