Upper GI Inflammation Flashcards
what are the causes of upper GI inflammation?
environmental (smoking, chemicals, drugs, viruses, bacteria)
hormonal secretion
genetic
host immunity
what are the outcomes of GI inflammation?
imbalance in mucosal protection
cell damage & metaplasia (abnormal turnover)
inflammation/irritation
what are the physical manifestations of upper GI inflammation?
abdominal pain
weight loss
diarrhoea
dysphagia (stuck food feeling)
fatigue
vomiting (possibly blood)
anaemia
nausea
ulceration
describe the cellular function of the stomach
simple columnar epithelium
all cells contribute to mucous secretion (covers most of internal surface)
adequate gastric acid protection
describe the cellular function of the oesophagus
non-keratinised stratified squamous epithelium
no mucous decretion unless goblet cell
less protection againest gastric acid
name the cells of gastric glands and their secretory products
surface mucous - mucin (alkaline fluid)
mucous neck - mucin (acidic fluid)
parietal cells - HCl/intrinsic factor
chief cells - pepsinogen/lipase
G cells (enteroendocrine) - gastrin
D cells (pyloric region) - somatostatin
what does gastrin stimulate?
enterochromaffin like cell (ECL) to produce histamine
parietal cells to produce acid
what does acetylcholine stimulate in the stomach?
G cells - gastrin
parietal cells - HCl
what does somatostatin inhibit?
ECL - histamine
what does histamine stimulate in the stomach?
HCl - parietal cells (H2 receptor)
HCl - D cell (H3 receptor) to inhibit somatostatin
what is the function of intrinsic factor in the stomach?
binds free vitamin B12 to be absorbed in terminal ileum
what is the function of HCl in the stomach?
pH 0.8
kills bacteria/viruses/parasites
optimises pH for pepsin action
what is the function of mucin in the stomach?
helps provide protection from auto-digestion by acid and pepsin
explain the physiology of GORD
reflux of acidic stomach content
incompetent lower oesophageal sphincter
what are the symptoms and exacerbation factors of GORD?
symptoms - burning, radiation behind sternum
exacerbation factors - bending/jumping/lying