GIT Pathology Flashcards
How long is the small bowel?
Approx. 6m
What are the three divisions of the small bowel?
Duodenum, jejunum and ileum
Which parts of the small bowel are retroperitoneal?
1st and 2nd part of the duodenum
What finger like projections line the small intestine?
Villi
What are villi covered in?
Microvilli
Why are villi covered in microvilli?
To increase SA
What is the function of goblet cells?
To secret mucous
What type of epithelium lines the small intestine?
Simple squamous
Why is rarity of cancer in the small intestine so surprising?
Because the cells renew ever 4-6 days meaning there is alot of opportunity for mutation
What is the colon divided into?
Caecum Ascending Transverse Descending Sigmoid
How is the colon peritonised?
Caecum Ascending - retro Transverse - intra Descending - retro Sigmoid
Is the rectum in the peritoneal cavity?
No it is out with
What are the 2 flexures of the colon?
Hepatic and splenic
Where is ischaemia common in the colon?
In the splenic flexure
Does the colon have villi?
No
Is cancer of the colon common?
Yes
What is the main cause of IBD?
Idiopathic
What is IBD?
Chronic inflammatory conditions resulting from inappropriate and persistent activation of the mucosal immune system driven by the presence of normal intraluminal flora
Is there a single causative organism for IBD?
No
What are the 2 main diseases in IBD?
Ulcerative colitis
Crohn’s Disease
Where can CD affect?
Anywhere from mouth to anus
Where does UC affect?
Only the colon
Which gene mutation is associated with CD?
NOD2
When does UC peak?
20-30
70-80 yrs
Can UC be localised to the rectum?
Yes
How does UC spread?
Proximally
What are some histological features of UC?
Inflammation of mucosa
Crypt abscesses
No granulomas
Does CD affect more F or M?
F
Does CD have granulomas?
Yes
What is a potential side affect of CD in the small intestine?
Malabsorption
Which IBD demonstrates skip lesions?
CD
Where does ulceration take place in CD?
Deep
Where does ulceration take place in UC?
Superficially
Which vessels are occluded in ischaemic enteritis?
Coeliac
SMA
IMA
What are the consequences of sudden major vessel occlusion?
Transmural injury
Acute/chronic hypoperfusion
Mucosa +/_ submucosal injury
What causes radiation colitis
Abdominal irradiation inflammation of your small and/or large intestine from radiation treatments in your stomach, sexual organs, or rectum.
Which type of radiation typically causes radiation colitis?
Rectum-pelvic radiotherapy
Which cells are targeted during radiation?
Actively dividing cells
What are the symptoms of radiation colitis?
Anorexia
Abdominal cramps
Diarrhoea
Malabsorption
What is the histological features of radiation colitis?
Later arterial stenosis Ulceration Necrosis Haemorrhage Perforation
How big are the appendix?
6-7cm
What type of organ is the appendix?
Lymphoid tissue ogran
What are the features of high grade colon dysplasia?
Carcinoma in situ
Crowded
Very irregular
not yet invasive
What are the features of low grade colon dysplasia?
Increased nucleus no.
Increased nucleus size
Reduced mucin
What is the most common type of Colorectal cancer/
Adenocarcinomas
What are the risk factors for colorectal cancers?
Lifestyle FH IBD UC and CD Genetics FAP HNPCC
What are the common symptoms of left sided colorectal cancers?
Bleeding
Altered bowel habit
Obstruction
What are the common symptoms of right sided bowel cancer?
Anaemia
Vague pain
Weakness
Obstruction
Which classification is used to stage colorectal cancers?
TNM
