pathology of the colon Flashcards
Describe the length of the small intestine
Duodenum - 25 cm
Jejunum - 2.5m
ileum - 3.5m
What innervates the peristalsis of the small and large intestine
Intrinsic - myenteric plexus
Extrinsic - autonomic control
Describe the myenteric plexus
Meissener’s plexus - base of the submucosa
Auerbach plexus - between the inner circular and outer longitudinal layers of the muscularis propria
What are the 2 main inflammatory bowel disease
Crohn’s disease
Ulcerative colitis
What parts of the body does crohns disease affect
Anywhere in the GI tract from the mouth to the anus
What parts of the body does ulcerative colitis affect
Colon
What gene is associated with Crohns disease and ulcerative colitis
NOD2 - Crohns
HLA - ulcerative colitis
What does a 1st degree relative do to the chances of getting inflammatory bowel disease
Increase - 15% of cases have a 1st degree relative affected
What is used to diagnose Inflammatory bowel disease
History
radiography
positive pANCA can help but not eliminate if negative
Who is most at risk of ulcerative colitis
M>F
20-30 and 70-80
Where in the colon does ulcerative colitis affect usually
Distal end of colon and spread proximally
What is backwash ileitis in ulcerative colitis
inflammation moves to the ileum from the caecum - only exception with ulcerative colitis not affecting the colon as well as appendix
Describe pathology of Ulcerative colitis
Continuous inflammation
Pseudopolyps
Ulceration
no granulomas
crypt abscesses
Doesn’t go through every layer of the tissue
Who is most at risk of Crohns disease
F>M
peaks 20-30 and 60-70 but any age
Caucasions and jewish population most common
Describe pathology of Crohns disease
Sharp demarcation between the skip lesions of affected tissue
Oedamatous
Cobblestone appearance with ulceration
Non caseating granulomas
Fibromas
Transmural inflammation - occurs throughout the entire wall
What is ischaemic colitis
Blood supply to the bowel is impinged - insufficient blood supply to the bowel which leads to cell death
What is enteritis
Inflammation of the small intestine
What does pain at McBurney’s point and pain that started at umbilicus and goes to right inguinal region suggest
Appendicitis
What increases the risk of colorectal adenocarcinoma
IBD
genetics;
FAP
HNPCC
peutz-jeghers
How does right sided colorectal adenocarcinoma present
Exophytic/Polypoid
Anaemia
Altered blood PR
Vague pain
Weakness
Obstruction
how does left sided colorectal adenocarcinoma present
Annular
Napkin ring lesion
Bleeding
Fresh/altered blood PR
Altered bowel habit
Obstruction
Why can left sided colorectal adenocarcinoma obstruct more than the right
The faeces have all the water absorbed by the time they get to the left side of the colon
