10.8 - Colon Flashcards
(46 cards)
hirschsprung disease is associated with that syndrome?
down syndrome
what is the cause of of hirschsprung disease?
due to congenital failure of ganglion cells to descend into myenteric and submucosal plexus
hirschsprung disease is due to congenital failure of _____________ to descend into _________ and _________ plexus
- ganglion cells
- myenteric and submucosal
the ganglion cells that fail to descend in hirschsprung disease are derived from ___________
neural crest cells
where is the myenteric (auerbach) plexus located? what is its role?
- between inner circular and outer longitudinal muscle layers of muscularis propria
- regulates motility
where is the submucosal (meissner) plexus located? what is its role?
- submucosa
- regulates blood flow, secretions, absorption
what type of biopsy is necessary to diagnosis hirschsprung disease?
rectal SUCTION biopsy (to get submucosa)
(false) colonic diverticula consist of outpouchings of ________ through the ______________
- submucosa
- muscularis propria
generally, where do colonic diverticula arise?
where the vasa recta traverse the muscularis propria
what part of the GI tract is the most common site of colonic diverticula?
sigmoid
what are the 3 main complications of colonic diverticula?
- rectal bleeding
- diverticulitis
- fistula
high stress in the left colon leads to _____________, whereas high stress in the right colon leads to ______________
- diverticula
- angiodysplasia
what is angiodysplasia?
acquired malformation of mucosal and submucosal capillary beds
what is the inheritance of hereditary hemorrhagic telangiectasia?
AD
ischemic colitis is most often due to atherosclerosis of the ______________
SMA
what are the two most common types of colonic polyps?
- hyperplastic
- adenomatous
which type of colonic polyp shows a “serrated” appearance on microscopy?
hyperplastic
where do hyperplastic polyps most often arise?
left colon (rectosigmoid)
are hyperplastic polyps benign or malignant?
benign
are adenomatous polyps benign or malignant?
benign but premalignant
the adenoma-carcinoma sequence involves what genes (in order)?
APC - KRAS - p53
which gene in the adenoma-carcinoma sequence is responsible for increased risk of formation of a polyp?
APC
which gene in the adenoma-carcinoma sequence leads to formation of a polyp?
KRAS
which gene in the adenoma-carcinoma sequence is responsible for progression to carcinoma?
p53
