GI, pancreas, liver etc Flashcards
(194 cards)
what types of cell make up the lining of the oesophagus?
squamous epithelial
non-keratinised
what are the sphincters at either end of the oesophagus called?
upper end = cricopharyngeal
lower end = gastro-oesophageal
how long is the oesophagus?
how much of the distal oesophagus is lined by glandular (columnar) mucosa? (ie distal to squamo-columnar junction)
what is the normal distance from the incisors to the squamo-columnar junction?
25 cm long
distal 1.5-2cm
40cm
what are the three main layers of the lining of the oesophagus?
what are the three sub-layers within the most superficial layer?
mucosa:
- epithelium (stratified squamous) - basal cell layer at bottom!
- lamina propria
- muscularis mucosae
submucosa
muscularis propria
oesophagitis:
- main infectious causes? 3 (with examples)
- main chemical causes? 2
infectious:
- viral (HSV1, CMV)
- fungal (candida)
- bacterial
chemical:
- reflux of gastric contents (most common!)
- ingestion of corrosive substances (mainly kids or self-harming adults)
on endoscope examination, what do these oesophageal infections look like:
- candida?
- herpes simplex?
candida = white plaques
herpes simplex = well-defined ulcers
what are the risk factors for reflux oesophagitis? 6
what is the commonest presenting symptom?
- obesity
- male
- defective lower oesophageal sphincter
- hiatus hernia
- increased intra-abdominal pressure
- increased gastric fluid volume (due to gastric outflow stenosis)
‘heart burn’
what is a hiatus hernia
what are the two different types of hiatus hernia?
what do they each tend to present with?
abnormal bulging of a portion of the stomach through the diaphragm
sliding hiatus hernia
- cardia bulges up
- reflux symptoms
paraoesophageal hiatus hernia
- fundus bulges up
- strangulation (can lead to necrosis + perforation)
what do the cells in reflux oesophagitis tend to look like (compared to normal)?
- basal cell hyperplasia
- increased inflammatory cells
basically more purple nuclei and less squamous cells
what are the potential complications of reflux oesophagitis? 5
- ulceration
- haemorrhage (at base of ulcers)
- perforation (if ulcer penetrates through wall)
- benign stricture
- BARRETT’S OESOPHAGUS
barrett’s oesophagus:
- cause?
- risk factors?
- macroscopy?
- histology?
cause:
- longstanding gastro-oesophageal reflux
risk factors:
- same as for reflux
macroscopy:
- proximal extension of squamo-columnar junction
histology:
- squamous mucosa replaced by columnar mucosa (called: glandular metaplasia)
what are the two types of barrett’s oesophagus? how do they differ?
normal barrett’s oesophagus
- no goblet cells
specialised barrett’s opoesophagus
- presence of goblet cell (norm found in small bowel)
what type of cancer can patient’s with barrett’s oesophagus develop?
- describe the 4 stages of this progression
how is this prevented?
adenocarcinoma of oesophagus
- barrett’s
- > low-grade dysplasia
- > high-grade dysplasia
- > adenocarcinoma
regular endoscopies
- freq determined by height of barrett’s + level of dysplasia
nb vast majority of people with barrett’s won’t get cancer!
what are the 2 main types of oesophageal cancer?
what are the:
- risk factors?
- geographical distribution?
- distribution in oesophagus?
adenocarcinoma
- risk factors: barrett’s, men, (maybe smoking, obesity)
- mainly caucasians
- mainly lower oesophagus
squamous carcinoma
- risk factors:
- –tobacco (main one)
- –alcohol
- –diet
- –thermal injury (very hot drinks)
- –human papilloma virus
- –male
- –black ethnicity
- mainly developing world
- middle + lower third (occasionally upper third)
what are the three different types of macroscopic appearance of oesophageal cancers?
- polypoidal (ie a lump)
- stricturing
- ulcerated
what staging system is used for oesophageal cancer?
TNM
(tumour, nodes, metastases)
nb in oesophageal cancer, ‘T’ focuses on depth of invasion through oesophageal wall
4 anatomic regions of stomach?
3 histological regions of stomach?
anatomic:
- cardia
- fundus
- body
- antrum
histological:
- cardia
- body
- antrum
nb body and fundus are histologically the same
what are the causes of gastritis due to:
- ‘increased aggression’? 7
- ‘impaired defenses’? 5
‘increased aggression’:
- excessive alcohol
- drugs (esp NSAIDs)
- heavy smoking
- corrosive
- radiation
- chemotherapy
- infection
‘impaired defenses’
- ischaemia (poor blood supply to stomach)
- shock (poor blood supply to stomach)
- delayed emptying (due to mass or stricture)
- duodenal reflux
- impaired regulation of pepsin secretion
what are the three most common causes of acute gastritis?
what are the possible complications? 2
- drugs (eg NSAIDs)
- alcohol
- initial response to helicobacter pylori infection
- erosion
- haemorrhage
nb generally heal quickly (if cause is removed)
what are three main causes of CHRONIC gastritis?
autoimmune
- anti-parietal + anti-intrinsic factor antibodies
- -> atrophy in gastric mucosa
bacterial infection (helicobacter pylori)
- majority get no disease
- 2-5% get gastric ulcers
- 10-15% get duodenal ulcers
chemical injury (NSAIDs, bile reflux, alcohol)
“ABC = causes of chronic gastritis”
what is MALT?
mucosa-associated lymphoid tissue
helicobacter pylori:
- type + shape of bacterium?
- where found in stomach?
- what does it result in, in stomach? 3
- gram negative
- spirillus
more common in antrum than body
- antrum is less acidic
- glandular atrophy
- replacement fibrosis
- intestinal metaplasia
what is the definition of a peptic ulcer?
at which 3 sites are they most common?
localised defect extending, at least, into SUBMUCOSA
- distal oesophagus (DOJ)
- junction of antral + body mucosa
- first part of duodenum
basically anywhere on the junction between different cell types
what are the main 5 causes of peptic ulcer disease?
- H.pylori infection
- duodeno-gastric reflux
- hyperacidity
- drugs (NSAIDs)
- smoking