The Appendix

Question 1

Layers of the colon wall

Answer 1

Mucosa, sub mucosa, inner circular muscle, outer longitudinal muscle, serosa

Question 2

Blood supply to the appendix

Answer 2

SMA to the ileocolic artery to the appendicular artery

Question 3

Function of the appendix

Answer 3

Immunologic organ that secretes immunoglobulins, particularly IgA. Integral part of the gut associated lymphoid tissue system. Vestigial organ.

Question 4

Epidemiology of appendicitis

Answer 4

Peaks in early adulthood and in elderly

Question 5

Causes of appendicitis

Answer 5

Lymphoid hyperplasia, fecalith, foreign objects (eg fruit seed), stricture, parasites (esp Ascaris)

Question 6

Obturator sign

Answer 6

Increased pain with internal rotation of right thigh

Question 7

What particular GI infection can especially mimic appendicitis?

Answer 7

Yersinia enterocolitis

Question 8

Imaging for appendicitis

Answer 8

CT with contrast. Graded compression ultrasound (not as sensitive but also good at ruling of gyn path)

Question 9

Mesenteric adenitis

Answer 9

Aka mesenteric lymphadenitis. Lymph nodes of the mesentery are inflamed. Usually resolves on its own. Can be caused by gastroenteritis. Also may be preceded by URI.

Question 10

Appendix development

Answer 10

Buds off the cecum. Origin is constant but the tip of appendix can be in various positions depending on the person. Lymphoid tissue develops two weeks after birth, grows, is constant for a time, decreases with age and is gone by 60 yrs old. At this point, complete obliteration of lumen is common.