Lymphatic drainage

Lymphatic drainage

Lymph from the upper half of the anal canal flows upwards to drain into the mesorectal lymph nodes and from there goes to the para-aortic nodes via the inferior mesenteric chain. Lymph Summary box 80.1 Anatomy and physiology of the anal canal /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF /uni25CF William Hamish Fearon Thomson , contemporary , surgeon, Gloucestershire Royal Hospital, Gloucester, UK. James Marion Sims , 1813–1883, gynaecological surgeon, State Hospital for Women, New Y ork, NY , USA, introduced this position to give access to the anterior vaginal wall during operations for the closure of vesicovaginal fistulae. into the superficial and then into the deep inguinal group of lymph glands.

The internal sphincter is composed of circular, non-striated involuntary muscle supplied by autonomic nerves The external sphincter is composed of striated voluntary muscle supplied by the pudendal nerve Extensions from the longitudinal muscle layer support the sphincter complex The space between sphincters is known as the intersphincteric plane The superior part of the external sphincter fuses with the puborectalis muscle, which is essential for maintaining the anorectal angle, necessary for continence The lower part of the anal canal is lined by sensitive squamous epithelium Blood supply to the anal canal is via superior, middle and inferior rectal vessels Lymphatic drainage of the lower half of the anal canal goes to inguinal lymph nodes