1
Q
What causes contraction of the internal anal sphincter?
A
Sympathetic innervation
2
Q
What causes relaxation of the internal anal sphincter?
A
Parasympathetic innervation
3
Q
What innervates the internal anal sphincter?
A
Pelvic sphlanchnic nerves
4
Q
What anatomical structure defines the point at which the rectum turns into the anal canal?
A
The levator ani
5
Q
What is the arterial supply to rectum and anal canal?
A
upper 2/3 - superior rectal (branch of the inferior mesenteric)
lower 1/3 rectum - middle rectal (branch of the internal iliac)
anal canal - lower rectal (branch of the internal pudenal artery)
