Fiser ABSITE Ch. 35 Small Intestine Flashcards
Function of: Small intestine? Large intestine?
Nutrient and water absorption; Water absorption
Duodenum anatomy: -Retroperitoneal portions? -Vascular supply?
-2nd and 3rd -Superior (off GDA) and inferior (off SMA) pancreaticoduodenal arteries
Jejunum: -Anatomy? -Function?
-100 cm long, long vasa recta, supplied by SMA -90% of water, 95% NaCl absorption
Ileum: -Anatomy -Function
-150 cm, short vasa recta, SMA supply -B12, folate and bile acid absorption
Short gut syndrome: -Diagnostic tests -Treatment
-Sudan red (fecal fat) -Schilling test (radiolabeled B12) -Fat restriction, PPI, lomotil
How much small bowel needed to survive with TPN in short gut?
75 cm or 50 cm with competent ileocecal valve; Meckel’s diverticulum (rule of 2’s)//2 FEET from ileocecal valve; 2 years old; 2% of population; 2 types of tissue (pancreatic, gastric)
How does Meckel’s present?
Bleeding in children. Obstruction in adults.
Segmental resection in Meckel’s?
-Neck > 1/3 of luminal diameter -Complicated diverticulitis -Diverticulitis involves base
Perianal disease in Crohn’s:
-First presentation in 5% -Presents as SKIN TAGS -Treat with FLAGYL
Medical treatment of Crohn’s
-Loperamide and 5-ASA -Steroids for acute flares -anti-TNF-alpha inhibitors for steroid-resistant or fistulas; 90% will need surgery
What cell type produces serotonin?
Kulchitsky (enterochromaffin) cells
Serotonin metabolism
Part of the amine precursor uptake decarboxylase (APUD) system. 5-HIAA is a breakdown product that can be measured in urine.
Carcinoid tumors release:
NAME?
Symptoms of carcinoid syndrome and treatment:
NAME?
Detection and localization of carcinoid?
Detect - Chromogranin A level; Localize - Octreotide scan
Small bowel carcinoid
Increased risk of MULTIPLE primaries and second unrelated malignancies
Carcinoid treatment
Depends on location: -Appendix:
Peutz-Jeghers syndrome
NAME?
Risk factors for duodenal adenocarcinoma
-FAP -Gardner’s -von Recklinghausen -polyps -adenomas
Leiomyosarcoma location
Extraluminal jejunum and ileum
Small bowel lymphoma
-Ileum -Associated with: Wegener’s, AIDS, celiac sprue, SLE, Crohn’s -NHL B cell type -Wide en bloc resection, NO WHIPPLE
Most common stomal infection?
Candida
Treatment of diversion colitis (Hartmann’s pouchitis)?
Short chain fatty acid enemas
Most common cause of stoma stenosis?
Ischemia
Most common cause of fistula near stoma site?
Crohn’s
Ileostomy increases risk of?
Gallstone; Uric acid kidney stones
Most common cause of appendicitis?
Hyperplasia - children; Fecalith - adults
Mucous papillary tumor of appendix
Appendix mucocele - should open to not spill contents - can get PSEUDOMYXOMA PERITONEI with rupture - SBO from peritoneal tumor spread MCC of death
Causative organism in typhoid
Salmonella
Treatment of typhoid enteritis
Bactrim
Symptoms of typhoid
NAME?
SMA eventually branches into?
Ileocolic artery
Intestinal brush border
Maltase, Sucrase, Limit dextrinase, Lactase
Cell types of small bowel: Absorptive cells
Goblet (mucin), Paneth (secretory granules, enzymes), Enterochromaffin (APUD, 5-HT release), Brunner’s glands (alkaline solution), M cells (APCs), Peyer’s patches
Migrating motor complex
Phase I - rest, Phase II - acceleration and gallbladder contraction, Phase III - peristalsis (motilin acts now), Phase IV - deceleration
