Surgery>>>>>Colon, Rectum, and Anus
Question 1#

A 74-year-old man with biopsy-proven rectal adenocarcinoma is undergoing a low anterior resection. Which layers must be stapled through when resecting the distal portion of resection specimen?

A) Mucosa, submucosa, circular muscle layer, longitudinal muscle layer, and serosa
B) Mucosa, submucosa, longitudinal muscle layer, circular muscle layer, and serosa
C) Mucosa, submucosa, longitudinal muscle layer, and circular muscle layer
D) Mucosa, submucosa, circular muscle layer, and serosa

Correct Answer is C

Comment:

The wall of the colon and rectum are made of five separate layers: mucosa, submucosa, circular muscle layer, longitudinal muscle layer, and serosa. The mid and lower rectum lack serosa so this layer would not be stapled through if the surgeon were stapling through the mid or lower rectum.