What are the muscles of the rectum?

The rectum is primarily supported by two layers of muscle: the inner circular layer and the outer longitudinal layer of the muscularis externa. Additionally, the puborectalis muscle, part of the pelvic floor, plays a crucial role in maintaining continence by creating an angle at the anorectal junction. The internal anal sphincter, made of smooth muscle, and the external anal sphincter, composed of skeletal muscle, also contribute to the control of bowel movements. Together, these muscles coordinate the functions of defecation and continence.