Appendix Flashcards
How do we locate the base of the appendix?
follow taeniae coli to confluence on cecum
In what instance do we find the appendix in the LLQ?
situs inversus
Situs inversus is a rare genetic condition where we have transposition of abdominal organs, and appendix is found where?
LLQ
When do we see appendix positioned in LUQ?
instance of midgut malrotation (midgut fails to rotate or incompletely rotates arounds SMA)
Blood supply of appendix?
appendicular branch of ileo-colic artery
Innervation of appendix?
SNS: superior mesenteric plexus, PSNS: vagus
What are the layers of the appendix?
outer serosa–>muscularis layer–> submucosa + mucosa
Appendix is an immunological organ secreting what?
IgA
Lifetime risk of developing appendicitis?
- 6% males
6. 8 % females
Main causes of acute appendicitis?
obstruction of lumen; fecalith vs hypertrophied lymph tissue
What causes umbilical pain in appendicitis?
lumen gets obstructed--> closed loop obstruction--> distention of lumen--> visceral afferent stretch fibers--> vague dull umbilical pain
Pathophysiology of appendicitis?
obstructed lumen continued distention bacterial overgrowth venous compromise arterial compromise perforation
What causes the RLQ abdominal pain assc with appendicitis?
inflammation that ultimately reaches serosal layer of appendix and then the peritoneum
What two bugs commonly found in appendicitis?
bacteroides fragilis
e. coli
Pts with perforated appendicitis or gangrene tend to have what bug more?
bacteroides
Describe the pain of appendicitis:
initially diffuse umbilical visceral pain
becomes more localized to RLQ as peritoneum involved
Psoas sign?
pain with right hip extension
Obturator sign?
pain with right hip flexion and internal rotation
Rovsign’s sign?
RLQ tenderness with palpation of LLQ
For uncomplicated appendicitis, it is unusual to have what?
leukocytosis >18 K
Most widespread scoring system for appendicitis?
ALVARADO score
Role of abdominal xrays in appendicitis work up?
can show fecaliths, but rarely helpful
CT vs US in diagnosing appendicitis, which is more sensitive and specific?
CT
What does appendix look like on US?
blind-ending non-peristaltic bowel loop originating from cecum