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Flashcards in GIT: Large Intestine Deck (32)
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1

describe Hirschsprung Disease

  • most common cause of congenital intestinal obstruction
  • associated with Down Syndrome
  • absence of ganglion cells in Meissner (submucosa) and Auerbach (myenteric) plexuses
  • rectum is always affected
  • dilatation and hypertrophy proximal to aganglionic segment (congenital megacolon)

2

there is an absence of ____ and ____ in Hirschsprung disease

there is an absence of ganglion cells in Meissner (submucosa) and Auerbach (myenteric) plexuses in Hirschsprung disease

3

Hirschsprung disease is associated with ____

Hirschsprung disease is associated with Down Syndrome

(RET mutation found in both)

4

describe the pathogenesis of Hirschsprung disease

5

in Hirschsprung disease, there is a defect in ____

in Hirschsprung disease, there is a defect in migration and survival of neuroblasts

6

describe the clinical features of Hirschsprung disease

  • delayed passage of meconium
  • constipation
  • abdominal distension
  • diagnosed by rectal biopsy​

7

list the complications of Hirschsprung disease

  • complication:
    • enterocolitis
    • perforation and peritonitis

8

describe the pathogenesis of diverticular disease

  • lack of dietary fiber leads to sustained bowel contractions and increased luminal pressure
  • herniation of colonic wall at sites of focal defects

9

diverticular disease pathogenesis:

lack of ___ leads to sustained bowel contractions and increased ____ → herniation

lack of dietary fiber leads to sustained bowel contractions and increased intraluminal pressure → herniation

10

list the 2 types of idiopathic inflammatory bowel disease

chronic relapsing, inflammatory disorder 

  • 2 main types
    • ulcerative colitis
    • Crohn disease

11

describe ulcerative colitis

diffuse involvement starting in the rectum and restricted to colorectum

  • histology:
    • mucosal and submucosal involvement
    • architectural distortion
    • dense chronic inflammation with basal plasmacytosis
    • cryptitis, crypt abscesses
    • no granulomas

12

ulcerative colitis starts in ____

ulcerative colitis starts in the rectum

13

name the condition in the image and describe the image

ulcerative colitis

sharp demarcation of abnormal from the neighboring normal

14

name the condition in the image and describe the image

ulcerative colitis

pseudopolyps can be seen

15

describe Crohn disease

  • ileal and colonic involvement
  • skip lesions
  • transmural inflammation, granulomas
  • fissuring ulcers, fistula, strictures
  • upper GI involvement and extraintestinal manifestations

16

ulcerative colitis is associated with ____

ulcerative colitis is associated with primary sclerosing cholangitis

17

ulcerative colitis has an association with HLA-____

ulcerative colitis has an association with HLA-DRB1

18

explain the etiology of pseudopolyps in ulcerative colitis

isolated islands of intervening regenerating mucosa bulge, creating pseudopolyps

19

Crohn disease is associated with HLA- ____

Crohn disease is associated with HLA- DR7 and DQ4

20

21

list the extraintestinal manifestations of IBD

  • seen in both CD and UC; can develop even before the onset of GI signs and symptoms
    • migratory polyarthritis
    • sacroileitis
    • ankylosing spondylitis
    • erythema nodosum
    • clubbing of finger tips
    • primary sclerosing cholangitis

SPACEM

22

fistulas are associated with (Crohns or UC)?

fistulas are associated with Crohns disease

23

describe the layers affected in UC vs. Crohns

UC = mucosa + submucosa

Crohns = all layers = transmural

24

describe amoebic colitis

  • caused by Entamoeba histolytica
  • parasitic infection (protozoan)
  • fecal-oral route
  • may resemble IBD on biopsy
  • chronic destructive colitis with flask-shaped ulcers
  • may involve liver, lungs, brain
  • treated with anti-parasitics

25

describe the image

26

describe the differences between TB and Crohn's

27

list causes of C. difficile colitis

  • clindamycin, ampicillin, cephalosporin and amoxicillin
  • can occur in patients with Hirschsprung
  • can occur during IBD relapse

28

describe the pathogenesis of pseudomembranous colitis

  • fibrinopurluent-necrotic debris (pseudomembranes)
    • surface epithelium denuded
    • superficially damaged crypts distended by mucopurulent exudate which erupts to form a mushrooming cloud
    • coalescence of these clouds leads to pseudomembrane formation

29

list clinical features of ischemic bowel disease

30

acute ischemic colitis can be caused by ____

acute ischemic colitis can be caused by E. coli

toxins lead to endothelial injury and hemorrhagic colitis