ANSWERS 100 VERIFIED)
1. EXAM
HIGH levels of HCL converts pepsinogen to pepsin
QUES- TION
What
converts
pepsinogen
to pepsin?
This decreases the acidity of venous blood from the stomach compared to
2. EXAM
the blood serving it.
QUES- TION
There is a Blood draining from the stomach is more alkaline than blood serving it
secondary (known as the alkaline tide);
trans- porter As the [HCO3-] increases, HCO3- leaves the basal cell membrane into
which ex- capillary blood, so blood draining from the stomach is more alkaline
changes than that arriving at it Cl- shift: HCO3- exchanged for Cl
HCO3- for Cl- , ATP binds to the K=/H+ ATPase which helps the counter transport of K+
What does this and H+: K+ in and H+ out into the gastric gland
effect have on
the blood?
(The bicarbonate that that is being pumped out will make that side of the cell
more alkaline than the blood that will be pumping to that side)
(slide 9)
3. EXAM QUESTION
draw out the
dia- gram with
labels for
gastric acid
secretion
4. LOs: -A brief outline of the gross and microscopic anatomy of the stomach
particularly in relation to its functions (see also anatomy and histology
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,Gastric acid secretion: Regulation (EXAM QUESTIONS AND
ANSWERS 100 VERIFIED)
sessions)
-A general introduction to the functions of the stomach and its secretions
-A simple demonstration of how gastric acid is made
A description of the control of gastric acid secretion in response to a
meal in terms
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, Gastric acid secretion: Regulation (EXAM QUESTIONS AND
ANSWERS 100 VERIFIED)
of the phases (gastric and cephalic) of secretion and the role of nerves
(vagus, hormones (gastrin) and local factors (somatostatin and
histamine)
-Outline how gastric acid secretion may become elevated and play a
role in the pathogenesis of duodenal ulcers describing the role of
Helicobacter pylori will be mentioned briefly.
-The role of non-steroidal anti-inflammatory (NSAIDs) drugs in the
gastric mucosal damage will be discussed.
5. What are the con- Contents of gastric juice (fasting state):
tent of gastric -Cations: Na+, K+, Mg2+, H+
juice -Anions: Cl-, HPO42+, SO42-
(fasting)? Pepsins
Lipase
Mucus
-Intrinsic factor
Gastrin mediates acid secretion via engaging with parietal cells and also via
6. What does histamine
gas- trin
mediate? Exocrine secretion of the stomach: mucus, acid, pepsinogen
7. What are the
ex- ocrine
secretions ofHCO3 - is exchanged for Cl- in the blood ’“of acidity of venous blood from
the stomach? stomach compared to blood serving it
Excess Cl- dittuses into the stomach through chloride channels as the H+ is
8. How is gastric
acid made in pumped into the stomach lumen (K+/H+-ATPase pumps H+ out into
the stomach stomach lumen)
lumen?
Net ettect = net flow of H+ Cl - out of the parietal cell and into stomach lumen
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