Rectum and Anal Canal Anatomy
Sigmoid colon, Peritoneal reflection, Rectosigmoid junction, Rectal
fascia, Longitudinal muscle layer, Circular muscle layer, Muscularis mucosae, Levator
ani muscle, Anorectal line, Anal columns (Morgagni’s), Anal sinus, Pectinate
(dentate) line, Internal rectal venous plexus in submucous space, Deep part* of
external sphincter muscle,
Conjoined longitudinal muscle, Internal sphincter
muscle, Anal valve, Anal crypt, Superficial part* of external sphincter muscle,
Anal glands, Transverse fibrous septum, Muscularis mucosae of anal canal perianal
space, Subcutaneous part* of external sphincter muscle, Corrugator cutis ani
muscle, External rectal venous plexus in perianal space, Intersphincteric
groove (anocutaneous line), Sweat glands and hairs in perianal skin, Anal verge,
Pecten, Anoderm Anatomical anal canal, Surgical anal canal *Parts variable and
often indistinct, Superior, Middle, Inferior, Transverse folds of rectum
(valves of Houston).
