3. Bowel Diseases Flashcards
Ischemic Bowel Disease
- watershed areas
Splenic Fixture
- SMA and IMA
Recto-sigmoid junction
- IMA and Internal Iliac A (hypogastric artery)
These areas with the least vasular collaterals between the dual supply - they are @ the borders of the territory of the arteries;
- hence most vulnerable to ischemia; possible diagnosis
- other areas have collateral circulation
Ischemic Bowel Disease effects - 4
Ischemia - Necrosis
- Muscles - diminished bowel sounds, pain after meals
- Mucosa - blood
- Transmural Perforation - Sepsis, Peritonitis, Shock
Healing - fibrosis - stricture - Obstruction
Celiac Disease, Histo, Cx
When eat gluten, immune system attack small intestine
- CD8 T cells
Histology
- Crypt Hyperplasia - crypts have stem cells hence to replace dying enterocytes
- Villus atrophy
- Lymphocytes
Malabsorption, Chronic Diarrhea
PMC
Clostridium Difficile
- Pseudo-membrane consists of inflammatory cells and debris
Acute appendicitis cause
Caused by obstruction, can perforate
TB histology
Langhan’s Giant Cells
Central Caseating Necrosis
Epithelioid Histiocytes
Amebiasis
Entamoeba Histolytica
- Dysentery
- Trophozoites invade epithelium, can go to liver to form abscess
- Friable, Hematophagous, CENTRAL karysome
Inflammatory Bowel Disease description and treatment
Inappropriate mucosal immune activation; Chronic
Treatment w immunosuppression
Crohn’s VS Ulcerative Colitis
Cx? 1 each
CD
- Involves colon + Terminal Ileum
- Skip lesions
- Transmural, deep ulcers, fistula
- Granuloma formation
- marked lymphocyte reaction, fibrosis and strictures
- Cx: Fat malabsorption
UC, has systemic presentations
- continuous
- Colon, rectum
- mucosal only w superficial ulcers
- pseudopolyps
- Cx: toxic megacolon - massive dilation after inflammatory damage
Diverticular Disease Complication!
Diverticulitis happens when diverticula become inflamed and in some cases infected.
Acute inflammation - diverticulitis
- Pericolic abscess, fibrosis, strictures, obstruction
- Colo-vesical fistula
- Perforation into peritoneal cavity
Diverticula does not involve the muscularis layer - taenia coli longitudinal ribbons of smooth muscle
Hirschsprung Disease
Aganglionic Megacolon Disease
- functional obstruction of the colon
Both meissner’s plexus (submucosal) and Auerbach
Obstruction Causes
Herniation
Intersussception
Volvulus
Adhesions
Vascular Obstruction - bowel infract (ischemia then strictures then infract)
Functional Obstruction - Hirschsprung Disease
GIT Histology
Mucosa - epithelium, lamina propria, muscularis mucosae
Submucosa - Meissner’s Plexus
Muscularis Propria - Circular Muscle, Myenteric/Auerbach Plexus, Longitudinal Muscle
Serosa/Adventitia
