
Sphincter Urethrae Muscle Quick Facts
Origin: Fibers of compressor urethrae muscle.
Insertion: Fibrous septum on posterior aspect of urethra.
Action: Constricts urethra.
Innervation: Perineal nerve (S2-S4).
Arterial Supply: Perineal artery.
Related parts of the anatomy
Sphincter Urethrae Muscle Origin
The fibers of the sphincter urethrae muscle are continuous inferiorly with those of the compressor urethrae muscle.
Sphincter Urethrae Muscle Insertion
The fibers of the sphincter urethrae muscle travel posteriorly, encircle the urethra, and insert onto the fibrous septum found along the posterior aspect of the urethra (Jung, Ahn and Huh, 2012).
Sphincter Urethrae Muscle Key Features & Anatomical Relations
The female external urethral sphincter muscle is one of the muscles of the deep perineal space, which itself is found in the urogenital triangle. It is a large, circular muscle that partly surrounds both the urethra and vagina in females.
It is located:
- anterior to the perineal body;
- superior to the perineal membrane;
- inferior to the urinary bladder.
For descriptive purposes, the female external urethral sphincter muscle is divided into three parts:
- a superiorly located sphincter urethrae muscle;
- an anteriorly located compressor urethrae muscle;
- a posteriorly located sphincter urethrovaginalis muscle (Jung, Ahn and Huh, 2012).
Sphincter Urethrae Muscle Actions
The female external urethral sphincter muscle constricts the urethra, keeping it closed and contributing to urinary continence. Its fibers relax during micturition (Standring, 2016).
Sphincter Urethrae Muscle List of Clinical Correlates
- Urinary incontinence
Sphincter Urethrae Muscle References
Jung, J., Ahn, H. K. and Huh, Y. (2012) 'Clinical and functional anatomy of the urethral sphincter', Int Neurourol J, 16(3), pp. 102-6.
Standring, S. (2016) Gray's Anatomy: The Anatomical Basis of Clinical Practice. Gray's Anatomy Series 41st edn.: Elsevier Limited.
