Stomach

Question 1

what are the 4 areas of the stomach

Answer 1

fundus
body
antrum
pylorus

Question 2

where does the oesophagus meet the stomach

Answer 2

cardia

Question 3

what is the main function of the stomach

Answer 3

mixing of gastric secretions into chyme

Question 4

what happens in the orad region of the stomach

Answer 4

no slow wave activity

weak tonic contractions move gastric contents into the caudad region

Question 5

what happens in the caudad region of the stomach

Answer 5

slow wave activity occurs

peristalsis pushes chyme along pylorus then retropulsion occurs

Question 6

what is retropulsion

Answer 6

rebound of chyme against distal antrum into the body to allow further mixing of chyme into small particles

Question 7

where in the stomach does most of the mixing of chyme take place

Answer 7

antrum

Question 8

what factors promote the emptying of the stomach (gastric factors)

Answer 8

large volume of chyme

thin consistency of chyme

Question 9

what factors delay the release of chyme (duodenal factors)

Answer 9

enterogastric reflexes

hormonal response - CCK and secretin

Question 10

what is the enterogastric reflex

Answer 10

duodenum signals to the stomach that it has enough chyme causing peristalsis to slow down

Question 11

where are the pyloric gland and oxyntic glands located

Answer 11

pyloric - antrum

oxyntic - fundus and body

Question 12

what cells are within pyloric gland and what do they secrete

Answer 12

D cells - somatostatin

G cells - gastrin

Question 13

what cells are within oxyntic gland and what do they secrete

Answer 13

parietal cells - HCl and intrinsic factor
enterochromaffin like cells - histamine
chief cells - pepsinogen

Question 14

what does intrinsic factor do

Answer 14

binds to vitamin B12 to help with digestion

Question 15

what do gastrin and histamine do

Answer 15

stimulate secretion of HCl

Question 16

what does somatostatin do

Answer 16

inhibit secretion of HCl

Question 17

how is HCl secreted from gastrin and histamine

Answer 17

CO2 and H2O form carbonic anhydrase - dissociates into H+ and HCO3
HCO3 is pumped out via antiporter exchanged for Cl-
Cl- is pumped out via CFTR channel
H+ leaves via proton pump and H+ and Cl- bind

Question 18

what are secretagogues and give examples

Answer 18

substances that stimulate production of HCl

eg histamine, gastrin and ACh

Question 19

what are the 3 phases of gastric secretions

Answer 19

cephalic phase
gastric phase
intestinal phase

Question 20

describe the cephalic phase

Answer 20

stomach prepared for good. conditioned by chewing/swallowing, causes increased gastric secretions from secretagogues

Question 21

describe the gastric phase

Answer 21

when food is in the stomach

distension of stomach causes mechanoceptors to increase secretions

Question 22

describe the intestinal phase

Answer 22

once the food has left the stomach

gastric secretions stopped through the release of CCK and somatostatin

Question 23

name groups of drugs that influence gastric acid secretion

Answer 23

PPIs
H2 receptor antagonists
Muscarinic receptor antagonists
NSAIDs

Question 24

what is contained within normal gastric mucosa to prevent irritation

Answer 24

contains mucus as physical barrier

contains HCO3 to buffer the mucosa

Question 25

what effect does prostaglandin have on mucosa

Answer 25

increases mucus and HCO3 production and increases blood flow therefore preventing gastric irritation

Question 26

what effect do NSAIDs have on gastric mucosa

Answer 26

inhibit prostaglandin production though COX1 causing less mucus and decreased blood flow - increases change of developing peptic ulcer and bleeding

Question 27

give an example of a PPI and when/route of administration

Answer 27

omeprazole | orally before breakfast

Question 28

how to PPIs work

Answer 28

inhibit the proton pump preventing secretion of acid | only active at low pH

Question 29

give an example of a H2 receptor antagonist and when to administer

Answer 29

ranitidine or cimetidine | take orally once/twice daily

Question 30

how do H2 receptor antagonists work

Answer 30

competitive antagonist of H2 receptor which reduces acid secretion from ACh

Question 31

what are the causes of acute gastritis

Answer 31

irritants/chemicals trauma severe burns

Question 32

what are the symptoms of acute gastritis

Answer 32

sudden onset of epigastric pain | vomiting (possibly with blood)

Question 33

what are the causes of chronic gastritis

Answer 33

autoimmune bacterial - H. Pylori chemical - NSAIDs alcohol

Question 34

what autoimmune conditions are associated with chronic gastritis

Answer 34

anti-parietal and anti-intrinsic factor antibodies - increased risk of malignancy with these conditions

Question 35

what are the symptoms of chronic gastritis

Answer 35

epigastric pain reflux vomiting feeling full after eating

Question 36

what are 4 complications of chronic gastritis

Answer 36

ulceration perforation bleeding stenosis

Question 37

what investigations are recommended for chronic gastritis

Answer 37

endoscopy | test for H. pylori

Question 38

what is the treatment for chronic gastritis

Answer 38

antacids, PPIs antibiotics if H. Pylori eat smaller more frequent meals

Question 39

what are benign gastric tumours known as

Answer 39

polyps - most common is adenoma

Question 40

what are the symptoms of polyps

Answer 40

usually asymptomatic but if perforate may cause bleeding

Question 41

what causes gastric polyps

Answer 41

chronic gastritis familial adenomatous polyposis (FAP genetic condition) drugs triggers typically PPIs

Question 42

do polyps need removed and why

Answer 42

yes - metastatic tissue that does have malignant potenial | removed at endoscopy on biopsy

Question 43

what types of malignant gastric cancers can arise

Answer 43

adenocarcinoma | lymphomas from MALT - mucosal associated gut lymphoid tissue

Question 44

what are the main symptoms of gastric cancer

Answer 44

weight loss anaemia haematemesis palpable mass

Question 45

how does H. pylori increase risk of developing cancer

Answer 45

H pylori - chronic gastritis - metaplasia - dysplasia - adenocarcinoma

Question 46

how and where is gastric adenocarcinoma likely to spread to

Answer 46

lymph nodes haematogenous - liver metastases direct invasion - ovaries and peritoneal cavity

Question 47

what is the treatment for gastric cancer

Answer 47

no mets - curative surgery | mets - palliation as chemo has little success

Question 48

what is gastroparesis

Answer 48

delayed gastric emptying

Question 49

what causes gastroparesis

Answer 49

``` idiopathic diabetes cannabis drugs eg opiates systemic disease (sclerosis) ```

Question 50

what are the classical symptoms of gastroparesis

Answer 50

feeling full easily nausea/vomiting upper abdominal pain weight loss

Question 51

what is the main treatment for gastroparesis

Answer 51

remove precipitating factor liquid diet/small portion pro-motility drug

Question 52

define peptic ulcer disease

Answer 52

breach in gastric mucosa by acid/pepsin due to imbalance of gastro-protective factors and mucosal injurious substances

Question 53

what are the main causes of peptic ulcer disease

Answer 53

H. Pylori infection NSAIDs idiopathic associated with IBS

Question 54

what are the symptoms of peptic ulcer disease

Answer 54

epigastric pain (radiates to back) relapsing/remitting symptoms pain relieved by eating - gastric ulcer pain on eating - duodenal ulcer

Question 55

what sort of bacterium is H. Pylori and how does it cause peptic ulcer disease

Answer 55

grame -ve flagellated bacillus | increases acid secretion causing erosion of the stomach

Question 56

how is H. Pylori spread

Answer 56

faecal-oral or oral-oral | acquired in infancy but doesnt cause disease until later life

Question 57

what investigations are required for diagnosing H. Pylori

Answer 57

urease breath test serology for IgA stool sample for FAT (faecal antigen test) possible endoscopy and biopsy

Question 58

if someone has H. pylori -ve peptic ulcer disease what is the treatment

Answer 58

anti-secretory therapy eg PPI and antacid | remove NSAIDs

Question 59

if someone has H. pylori +ve peptic ulcer disease what is the treatment

Answer 59

triple therapy | PPI + amoxicillin + clarythromycin for 1 week

Question 60

what are the main complications of peptic ulcer disease

Answer 60

bleeding perforation anaemia

Question 61

where in the GI tract is a peptic ulcer more likely to arise

Answer 61

duodenum followed by stomach

Question 62

functional dyspepsia is more common than organic dyspepsia true/false

Answer 62

true

Question 63

which individuals are at risk of developing GI infections

Answer 63

``` malnutrition deficiencies immunocompromised individuals closed communities eg ward extremes of age gastric acid secretion suppression ```

Question 64

what is dysentry

Answer 64

inflammation of the intestine esp colon | causes bloody diarrhoea with mucus and associated with gastroenteritis

Question 65

name some organisms causing gastroenteritis that have short incubation times (1-6 hours)

Answer 65

staph aureus | bacillus cereus

Question 66

name some organisms causing gastroenteritis that have medium incubation times (12-48 hours)

Answer 66

salmonella | C. perfringes

Question 67

name some organisms causing gastroenteritis that have long incubation times

Answer 67

campylobacter | E. Coli 0157