GI Flashcards
what does the upper GI tract involve
mouth, oesophagus, stomach and duodenum
what is the most common problem with the oesophagus
Barrett’s oesophagus (and oesophageal cancer )
what stops reflux into the oesophagus (2)
cardiac sphincter
diaphragm constricting around the lower oesophagus
why is it important that we prevent acid reaching the oesophagus
mucous is needed to protect epithelium from acid
only glandular epithelium has mucous (stomach)
if acid reaches non-mucous lined squamous epithelium of the oesophagus, it is destroyed and acid then can ulcerate the tissue
compare the epithelium of the oesophagus and the stomach
oesophagus = non-keratinised stratified squamous epithelium
stomach= non-keratinized simple columnar epithelium with mucous glands
how might we diagnose barrettes disease (4)
endoscopy
normal oesophageal tissue is white and reflective
if red tissue is found in the lower oesophagus, this is columnar epithelium from the stomach growing
what is barrettes oesophagus
where we get metaplasia from stratified squamous epithelium in the oesophagus to columnar epithelium from the stomach
what is another name for barretts oesophagus
columnar lined lower oesophagus - CELLO
explain the mechanism of barrettes oesophagus
IF the acid refluxes, acid goes into the oesophageal epithelium and these cells cannot cope with low pH so they die.
This leads to no epithelium, ulceration and pain.
Squamous epithelial CAN regrow but if the acid keeps refluxing, then we get metaplasia or growth from epithelium from the stomach into the oesophagus.
what might barrettes oesophagus predispose and why
barrettes oesophagus has columnar epithelium in the oesophagus
This is not meant to be and is genetically unstable so predisposes oesophageal cancer
constant acid attack will constantly damage tissue and also increase chances of cancer
why is adenocarcinoma of the oesophagus infinitely increased chances with people with barrettes oesophagus
people without barrettes oesophagus cannot get oesophageal adenocarcinomas as this is cancer of glandular tissue
normal oesophageal tissue is not glandular so cannot get adenocarcinoma
what are some risk factors for barrettes oesophagus (3)
increased wieght = abdominal pressure increase on stomach contents
male
late age >50
why might oesophageal cancers be eligibly on the rise (2)
ageing population and old onset so more diagnosis
no longer grouped with gastric cancers
in asia and africa there are very high levels of oesophageal cancers. compare this cancer to the type of oesophageal caner found in europe.
Asia and Africa are commonly squamous cell carcinomas due to alcohol and smoking
Europe are usually barrettes related = adenocarcinomas
compare oesophageal adenocarcinomas and squamous cell carcinomas
AC = barrettes oesophagus, reflux, weight, age, europe
SCC = asia, africa, smoking and alcohol
give 2 reasons why oesophageal cancer has low prognosis
often not diagnosed until late stage so low prog
very close to important structures e.g. trachea, aorta, vena cava so can have very bad consequences if metastatic
what is Helicobacter Gastritis caused by
Helicobacter Pylori H. Pylori
what is the strcutre of H.Pylori (3)
rod shaped bacilli
motile
flagellum
how is Helicobacter Gastritis caused (3)
hide in the mucous layer of stomach
This bacteria produces chemicals that attract in inflammatory cells eg. neutrophils into the stomach, causing acute inflammation.
This causes ulceration in the stomach allowing acid to reach under the epithelium.
where do H.Pylori live
mucous layer of the stomach
how do we treat Helicobacter Gastritis
1 week
Antibiotic e.g. metronidazole
why is the incidence of gastric cancer reducing with time (2)
oesophageal cancer no longer included in ‘gastric cancers’ and they made up a large proportion of this
less frying with cast rion pans that = nitrosamines = carcinogen
where do we find high gastric cancer incidence, why?
east asia and eastern europe
high amounts of smoked and pickled foods - acidic
how do we treat acid reflux (3)
anti-acids e.g. Gaviscon
proton pump inhibitors e.g. Omeprazole or Lansoprazole
surgery