She has had no previous episodes of this nature and is otherwise healthy with no medical problems. She takes no medications. Her chest is clear to auscultation. The abdomen is remarkable for guarding localized tenderness of the right lower quadrant. Peritoneal signs are present with midabdominal percussion.
Rectal exam reveals right sided tenderness and guaiac negative stool.
Pelvic examination also reveals mild right sided tenderness but otherwise normal adnexa and cervix. Laboratory examination reveals a normal hemoglobin and hematocrit. Her WBC is13,400 with 11 bands. Urinalysis is normal. Describe the pathophysiology of acute appendicitis.