Upper GI Flashcards
Describe the normal oesophageal epithelium
starts as squamous epithelium
Z line - transition
Becomes columnar epithelium
What is the Z line
the point at which the epithelium transitions from squamous to columnar
What does the esophageal epithelium contain
submucosal glands
what does the gastric columnar epithelium of the body and fundus of the stomach contain/produce?
SPECIALISED GLANDS
Produce acid + intrinsic factor
what is the function of intrinsic factor
accompanies B12 for absorption in the terminal ilieum
what happens without intrinsic factor?
in pernicious anaemia, antibody against intrinsic factor
means B12 cannot be absorbed > anaemia
What kind of epithelium lines the stomach?
gastric mucosa columnar epithelium
What does the epithelium in the pylorus and antrum produce?
gastrin
Describe the epithelium in the normal duodenum
Glandular epithelium
wtih goblet cells
What is the villous to crypt ratio in the duodenum
villous : crypt = 2:1
Why are villi important
for absorption
so if this ratio diminishes, it means malabsorption is occurring > find underlying disease
Are goblet cells normally seen in stomach?
NO > feature of metaplasia
What usually causes oesophagitis
GORD
what are unwanted consequences of GORD
Ulceration, fibrosis, haemorrhage, perforation, stricture,
BARRETS OESOPHAGUS
what is barret’s oesophagus
normal squamous epithelium of the lower oesophagus is replaced by METAPLASIC columnar epithelium
what are the three layers in the oesophagus
epithelium (squamous/columnar)
submucosa
Muscolaris
is Barrets reversible
YES
What occurs in intestinal metaplasia
GOblet cells become visible in the stomach
explain the transition from healthy oesophagus to cancer
acid rises up from stomach e.g. gord > metaplasia from squamous to columnar > persists > dysplasia
What is the most common type of oesophageal cancer in West
ADENOCARCINOMA
what are RF for adenocarcinoma
Barrett’s
GORD
Where does adenocarcinoma occur
Lower 1/3 of oesophagus
What is seen on histology of the adenocarcinoma
glandular (columnar) epithelium
What part of the oesophagus is most affected in adenocarcinoma
lower 1/3
WHere is SCC the most common tuype of oesophageal cancer
In developing countries
what is oesophageal SCC associated with
smoking, alcohol
what part of the oesophagus is most affected in SCC
lower 2/3
what is seen on histology of SCC
keratrinised cells, IC bridges
What is gastritis
inflammation of gastric mucosa
what are causes of gastritis
ABC
Autoimmune
Bacteria: H pylori
Chemicals: alcohol, NSAIDS, corrosives
What is an example of c hornic gastritis causing severe damage
chronic gastritis associated with H pylori induces lymphoid tissue in stomach > dev elipmeent of lympohoid follicles > increased risk of MALT lymphoma
What is the MOA of H pylori
bind to epithelial cells
inject. toxins into theme
summarise consequences of H pylori gastritis
dysplasia
adenocarcinoma
lymphoma (MALToma)
what is the toxin secreted by H pylori
Cag A
what is a gastric ulcer
depth of tissue loss beyond the mucosa, into the submucosa
what is an erosion
loss of surface epithelium and lamina propria (NOT beyond the mucosa)
what is the difference between an acute and chronic ulcer
a chronic ulcer presents with SCARRING and FIBROSIS
what should you do for all patients presenting with an ulcer
BIOPSY it
TO EXCLUDE MALIGNANCY
what is the most common type of malignant gastric cancer
ADENOCARCINOMA
what are the two types of gastric adenocarcinoma
intestinal
diffuse
describe an intestinal gastric adenocarcinomna
has all features of intestinal mucosa
well differentiated
presence of glands containing muciin
describe an diffuse gastric adenocarcinomna
no identifiable features, poorly differentiated
composed of single cells, no attempt at gland fomrartion
what are the two types of diffuse adenocarcinoma
Linitis plastica
Signet ring cell carcinoma
what are histological features of coeliac
villous atrophy
crypt hyperplasia
increased intraepithelial lymphocytes
why is it bad that villous atropby occurs
villi flatten > less area for absortpion > malabsorption
What is lymhocytic duodenitis
PRECURSOR TO COELIAC
there are inflammatory changes (increased intraepithelial lymphocytes ) without architectural changes
what antibodies are used to diagnose coeliac disease
Endomysial antibodies
Tissue transglutaminase antibodies (IgA)
what must you also measure when measuring TTA
total serum IgA > because if they have selective IgA deficienncy they will not have TTAs
What is the gold standard for coeliac dx
duodenal biopsy - on gluten rich diet
what is tropical sprue
another cause of malabsorption
similar histology to coeliacs
but occurs in tropical countries, where there are different bacterial types
