State the name of the bacterium that can cause stomach ulcers.

Compare and contrast the effect of adding antioxidants to nizatidine on the ulcer healing rate.

Components of gastric juice have been thought to aggravate the development of ulcers. Outline the role of nerves in the secretion of gastric juices.

Gastric juice production can be inhibited by the hormone secretin which is a polypeptide. Outline the mechanism by which a peptide hormone carries out its function.

Helicobacter pylori ✔

To award [1] full scientific name is required.

a. vitamin E and thioctic acid both improve healing rate «compared with nizatidine alone»
OR
all trials with antioxidant/three trials improve healing rate «compared to N alone» ✔

b. adding vitamin E increases healing rate more than adding thioctic acid
OR
adding both vitamin E and thioctic acid increases healing rate to highest level «but still less than 100 %» ✔

Giving values alone is not enough.

[Source: Effect of Helicobacter Pylori
Eradication Therapy and some Antioxidants
on Ulcer Healing Rates in Patients with
Helicobacter pylori-associated Duodenal
Ulcer, Ahmed M Ali, 2013, http://
www.rroij.com/open-access/effect-ofhelicobacter-
pylori-eradication-therapy-andsome-
antioxidants-on-ulcer-healing-rates-inpatients-
with-helicobacter-pylor-.php?
aid=34774, licensed under a Creative
Commons Attribution 4.0 International
License]

a. sight/smell of food stimulates brain ✔

b. food entering stomach stimulates chemoreceptors/stretch receptors to send impulses/signals to brain ✔

c. impulse/signal from brain causes cells in stomach lining/parietal cells to secrete acid/HCl/gastric juice ✔

d. brain sends impulses/signals «via vagus nerve» to endocrine cells in wall of stomach to release gastrin ✔

e. gastrin stimulates «more» production of acid/HCl/gastric juice ✔

a. bind to plasma membrane receptors of «target» cell ✔

b. results in activation/release/synthesis of a secondary messenger ✔

c. triggers a cascade of reactions ✔

d. leads to promotion/inhibition of enzymes
OR
causes activation of protein kinase «resulting in hormonal effect» ✔

A large number stated the complete binomial name, as expected; many provided only a partial name; a noticeable number wrote E. coli, something else irrelevant or left the box blank.

The majority could contrast the effect, but it was more difficult for some also to provide a comparison, that is, similarities; many had some difficulty organizing their answer, although correct.

The majority had a good idea about factors that would increase gastric juice secretion, but a large number bypassed the role of the brain or the nerves in their answer, limiting themselves to the various stimuli and responses.

Many candidates provided a correct, complete answer. Some nevertheless inverted the order of the production of a second messenger and the cascade of reactions, which occurs afterwards to cause the multiplying effect of the hormone. A noticeable number, especially in French, outlined the action of secretin in digestion instead of answering the question. A few confused peptide hormones with steroid hormones.