7.1 Colon & IBD Flashcards
(23 cards)
why does colon remove water form gut contents?
create thick mucous layer
which parts of large intestine are retro-peritoneal?
ascending, descending colon, middle 1/3 rectum
which parts of colon have their own mesenteries?
sigmoid
transverse
level of SMA
L1
arterial supply to midgut
-caecum: ilio colic
-ascending: right colic
-transverse: middle colic
arterial supply to hindgut
-descending: left colic
-sigmoid: sigmoid
-upper 1/3 rectum: superior rectal (IMA)
level of IMA
L3
venous drainage of
1. midgut
2. hindgut
3. upper 1/3 rectum
4. middle+lower rectum
5. foregut
- SMV
- IMV
- superior rectal (IMV)
- systemic venous system
- splenic vein
site of postosystemic anastomoses
middle ad lower rectum drain into systemic venous system
where doe most water absorption occur in colon?
proximal colon
purpose of tighter tight junction
in colon
bigger gradient so less back diffusion of ions
how much water enters and exits colon per day?
1500mL in
100mL out in faeces
common target of crohns
terminal ileum = RLQ tenderness, mass
result of crohns being transmural
fistulae, strictures
gross patholigical changes in crohns
-skip lesions
-hypereamia
-mucosal oedema
-discrete superficial ulcers
-transmural inflammation (wall thicker, narrow lumen)
why’s there mucous in UC stool?
superficial mucous layer of bowel disturbed
why’s pain less localised in UC?
continuous damage
why’s there crypt distortion in UC?
superificcial muscle heals in a distorted way
what causes development of pseudo polyps?
repeated inflammation then healing
risk of colonoscopy in UC
bowel perforation
why do we aim to remove as little bowel as possible in crohns?
could cause bowel to be too short so not enough water absorbed so constant diarrhoea
could cause obstruction, pain
in UC colectomy, what could there rectum be reattached to?
terminal ileum
is there more bleeding in UC or crohns?
UC
