The Stomach

Question 1

what are the 3 regions of the stomach?

Answer 1

the cardia, fundus and antrum

Question 2

what do parietal cells do

Answer 2

produce HCl

Question 3

what stimulates parietal cells

Answer 3

gastrin, histamine and ACh (from the vagus nerve)

Question 4

what is the alkaline tide

Answer 4

during H+ production in the parietal cells, bicarb is also produced, which moves into the blood vessels draining the stomach making the blood here temporarily more alkaline

Question 5

why do parietal cells require lots of mitochondria

Answer 5

they need lots of energy to use the proton pump against a large concentration gradient

Question 6

what do chief cells do

Answer 6

produce pepsinogen

Question 7

what do G cells produce

Answer 7

gastrin

Question 8

what stimulates G cells

Answer 8

vagus nerve secreting ACh

amino acids in the stomach

Question 9

what does gastrin do

Answer 9

activate parietal cells

Question 10

what inhibits gastrin production

Answer 10

somatostatin

Question 11

what do enterochromaffin cells do

Answer 11

secrete histamine

Question 12

what role does histamine have in the stomach

Answer 12

activates parietal cells

Question 13

what do D cells do

Answer 13

secrete somatostatin

Question 14

what does somatostatin inhibit in the stomach

Answer 14

G cells and ECL cells

Question 15

what are the roles of stomach acid

Answer 15

• part of the innate immune system
• chemical digestion
• converts pepsinogen into pepsin

Question 16

what types of cells are mostly found in the cardia of the stomach

Answer 16

mucus secreting cells

Question 17

what types of cells are mostly found in the Antrum of the stomach

Answer 17

G cells and D cells

Question 18

what does the stomach do to help protect itself

Answer 18

• mucus secretion
• prostaglandins
• high turnover of epithelia

Question 19

what do prostaglandins do in the stomach

Answer 19

increase blood flow to the stomach - this brings more nutrients to the epithelia

Question 20

what inhibits prostaglandin productions

Answer 20

NSAIDs like aspirin

Question 21

how does alcohol affect the stomach

Answer 21

dissolves the mucus layer

Question 22

what are the 3 phases of digestion in the stomach

Answer 22

cephalic
gastric
intestinal

Question 23

what happens in the cephalic phase of digestion

Answer 23

the smell and chewing of food stimulates parietal and G cells though the vagus nerve

Question 24

what happens in the gastric phase of digestion

Answer 24

stomach distension activates parietal and G cells
amino acids activate G cells
enteric NS causes smooth muscle contractions

Question 25

what happens in the intestinal phase of digestion

Answer 25

chyme in the duodenum stimulates gastrin production before the G cells become inhibited

Question 26

what stimulates D cells

Answer 26

when food leaves the stomach, the pH drops as it is no longer being buffered
the lower pH activates the D cells

Question 27

what test can be done to diagnose h-pylori

Answer 27

urease breath test

Question 28

what does the urease enzyme do

Answer 28

converts urea into ammonium

Question 29

how can urease damage the stomach

Answer 29

the ammonium produced is directly toxic to cells

Question 30

how does h-pylori cause damage

Answer 30

• through ammonium production which is toxic

- is cytotoxic to the epithelia itself

Question 31

if h-pylori is found in the Antrum what will it cause

Answer 31

duodenal ulceration

Question 32

if h-pylori is found in the body what will it cause

Answer 32

stomach cancer

Question 33

give an example of a proton pump inhibitor

Answer 33

omeprazole

Question 34

give an example of a H2 antagonist

Answer 34

cimetidine

Question 35

what ways are there to treat stomach problems

Answer 35

proton pump inhibitors
H2 antagonists
stop NSAIDs
antibiotics for H-pylori

Question 36

what is GORD

Answer 36

where the stomach contents moves into the oesophagus

Question 37

what causes GORD

Answer 37

lower oesophageal sphincter problems
obesity
hiatus hernia
delayed stomach emptying

Question 38

what symptoms are seen in GORD

Answer 38

heart burn
cough
sore throat
dysphasia

Question 39

what is Barrett’s oesophagus

Answer 39

where reflux causes metaplasia of the stratified squamous epithelia of the oesophagus to convert into simple columnar - increasing the risk of adenocarcinoma

Question 40

how do you treat GORD

Answer 40

antacids
H2 antagonists
proton pump inhibitors

Question 41

what is gastritis

Answer 41

inflammation of the lining of the stomach

Question 42

what may cause acute gastritis

Answer 42

NSAID use, alcohol, chemotherapy

Question 43

what may cause chronic gastritis

Answer 43

h-pylori, autoimmune disease attacking parietal cells

Question 44

why may an autoimmune disease against parietal cells cause anaemia

Answer 44

as parietal cells produce intrinsic factor which helps in vitamin B12 absorption - without vitamin B12 you will develop anaemia

Question 45

what type of anaemia is developed from a lack of vitamin B12

Answer 45

pernicious anaemia

Question 46

what is peptic ulcer disease

Answer 46

where the mucosa is eroded down through the muscularis mucosa layer

Question 47

what may cause peptic ulcer disease

Answer 47

NSAIDs, h-pylori, stomach acid

Question 48

what are the symptoms of peptic ulcer disease

Answer 48

epigastric pain, weight loss, bleeding (if a vessel is eroded through)

Question 49

why may you get epigastric pain with peptic ulcers

Answer 49

as the stomach is a foregut structure

Question 50

what is Zollinger-Ellison disease

Answer 50

where theres a gastrin secreting tumour - this causes an up regulation of parietal cells causing increased acid production

Question 51

what can cause stress ulcers

Answer 51

burns, sepsis, trauma, multi organ failure