Subcutaneous part of external anal sphincter
Pars subcutanea sphincteris externi ani
- Related terms: Subcutaneous part
Definition
The subcutaneous part of the external anal sphincter is the most distal portion of the external anal sphincter, located below the internal anal sphincter. It is the only muscle encircling the anus (anal orifice) below the internal anal sphincter and is responsible for maintaining anal continence providing a tight seal at the anal opening.
The subcutaneous part of the external anal sphincter appears as two parallel muscle strips in the axial plane and as the J-shaped part in some anatomical descriptions, highlighting its unique configuration and its integration with the lower margin of the internal anal sphincter.
References
Correlation Between Gross Anatomical Topography, Sectional Sheet Plastination, Microscopic Anatomy and Endoanal Sonography of the Anal Sphincter Complex in Human Males.Al-Ali S, Blyth P, Beatty S, et al.Journal of Anatomy. 2009;215(2):212-20. doi:10.1111/j.1469-7580.2009.01091.
Cross-Sectional Imaging Anatomy of the Anal Sphincters.Peschers UM, DeLancey JO, Fritsch H, Quint LE, Prince MR.Obstetrics and Gynecology. 1997;90(5):839-44. doi:10.1016/S0029-7844(97)00406-7.
Magnetic Resonance Imaging and 3-Dimensional Analysis of External Anal Sphincter Anatomy.Hsu Y, Fenner DE, Weadock WJ, DeLancey JO.Obstetrics and Gynecology. 2005;106(6):1259-65. doi:10.1097/01.AOG.0000189084.82449.fc.
A Missing Distal Complex of the External and Internal Anal Sphincters: A Macroscopic and Histologic Study Using Japanese and German Elderly Cadavers.Ishiyama G, Kim JH, Chai OH, et al.Surgical and Radiologic Anatomy : SRA. 2021;43(5):775-784. doi:10.1007/s00276-020-02606-4.
