L20: Inflammatory Diseases of the Bowel Flashcards
(44 cards)
What parts of the large intestine does the superior mesenteric artery supply?
caecum to the splenic flexure
What part of the large intestine does the inferior mesenteric artery supply?
splenic flexure to rectum
What is the main function of the large intestine?
- absorb water + salts
- remove waste products
The large intestine does not have any villi. True or False?
True
Where is Meissner’s plexus located in the large intestine?
in the submucosa
Where is the Auerbach/Myenteric plexus located in the large intestine?
muscularis propria
Which parts of the large intestine does Hirschsprung’s Disease normally affect?
sigmoid colon + rectum
What is Hirschsprung’s Disease?
- congenital megacolon
- aperistaltic, narrow segment present causing a functional obstruction and dilation of proximal colon
- a/w RET gene mutation
Why does Hirschsprung’s Disease occur? (pathogenesis)
- arrested migration of parasympathetic neural crest cells into bowel wall
- absence of ganglion cells in Auerbach and Meissner’s plexus
Which mutation is associated with Hirschsprung’s Disease?
RET gene mutation
What is the clinical presentation of Hirschsprung’s Disease?
failure to pass meconium, constipation, abdominal distension, vomiting
What is the treatment of Hirschsprung’s Disease?
resection of the involved bowel
What are the 4 types of ischaemic bowel disease that affect the large intestine?
- Transmural Infarction
- Mural Infarction
- Mucosal Infarction
- Chronic Ischaemic Colitis
What is mural infarction of the large intestine?
necrosis of the mucosa and submucosa
What is mucosal infarction of the large intestine?
necrosis of the mucosa only
Mural and/or mucosal infarction of the large intestine is mainly caused by what?
hypoperfusion - especially in watershed areas
What are the clinical features/symptoms of a transmural infarction?
- severe abdominal pain
- bloody diarrhea
- decreased persistaltic sounds
- rigidity
What is angiodysplasia of the large intestine? Where does it normally occur?
- breakdown/dilatation of blood vessels
- usually in caecum and right colon
- usually in elderly
What is hereditary haemorrhagic telangiectasia?
- autosomal dominant disorder
- thin walled blood vessels in the mouth and GIT
- may rupture and bleed
What are haemorrhoids? How do they present?
- variceal dilatation of submucosal venous plexi around anus and lower rectum
- can be inside anus or on skin around anus
- presents w/ bright red stool and painful swelling around anus
What is necrotising enterocolitis? Which population does it occur in?
- occurs in neonates (occurs usually between day 2-4; up to 3 months)
- – premature + low birth weight infants
- acute necrotising inflammation of small and large bowel
Which population is necrotising enterocolitis most likely to occur in?
premature infants or low birth weight infants
Why does necrotising enterocolitis occur? [4]
combination of:
- ischaemia
- colonization of pathogenic organisms
- excess protein in lumen
- functional immaturity of gut
What is another name for pseudomembranous colitis?
antibiotic-associated colitis