[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Anatomy](https://durgical.com/en/anatomy/) › [Pelvis · Male](https://durgical.com/en/anatomy/region/pelvis/) › Epididymis [Reproductive system](https://durgical.com/en/anatomy/system/reproductive-system/) · [Pelvis · Male](https://durgical.com/en/anatomy/region/pelvis/) # Epididymis The epididymis is a coiled tube along the back of each testis; it stores sperm and lets them mature until they can swim. [See in 3D →](https://durgical.app/?from=durgipedia&lang=en#region=pelvis&variant=male&select=epididymis&side=r) Opens in the Durgical app, no sign-up needed. ## What it is A tightly coiled tube, about 6 m long if uncoiled, packed into a comma-shaped structure along the back of the testis: head, body and tail. ## What it does Stores sperm and lets them mature so they gain the ability to swim; its tail continues as the ductus deferens. ## Key points - Epididymitis begins more gradually than torsion, often with fever and urinary symptoms, and the tenderness sits at the back of the testis; Doppler ultrasound settles the doubt - Usual causes by age: sexually transmitted organisms (chlamydia, gonorrhoea) in younger sexually active men; bowel bacteria from urinary infection or obstruction in older men - A mass in the epididymis is usually benign; a mass in the testis itself is treated as cancer until proven otherwise - Spermatoceles arise from its head: felt separate from and above the testis, and they let light through ## Key facts **Where** Along the posterolateral border of the testis: head (upper pole, receives the efferent ductules), body and tail (lower pole), which continues as the ductus deferens **Blood supply** [Testicular artery](https://durgical.com/en/anatomy/testicular-artery-pelvis/); artery to the ductus deferens (tail); veins to the pampiniform plexus **Nerve** Autonomic fibres of the testicular plexus and of the pelvic plexus along the ductus deferens **Function** Stores, concentrates and matures sperm (they gain motility); epididymitis is a common cause of scrotal pain; spermatoceles arise from it ## Relations **In front** [Testis](https://durgical.com/en/anatomy/testis/), joined at the head by the efferent ductules; laterally a recess of the tunica vaginalis separates its body from the testis **Above** Head at the upper pole of the testis, often carrying the [appendix](https://durgical.com/en/anatomy/vermiform-appendix/) of the epididymis **Below** Tail at the lower pole, continuing as the [ductus deferens](https://durgical.com/en/anatomy/ductus-deferens/), which turns up along its medial side **Behind** [Spermatic cord](https://durgical.com/en/anatomy/spermatic-cord/) vessels and the scrotal wall ## How to find it Felt along the back of the testis as a soft ridge, thicker above (head) and below (tail), normally a little tender; the ductus deferens rises from the tail. ## Examination - Prehn sign: lifting the [scrotum](https://durgical.com/en/anatomy/scrotum/) eases pain in epididymitis but not in torsion; only a supporting sign - Cremasteric reflex: usually present in epididymitis, often absent in torsion - Transillumination: a spermatocele lets light through; a solid mass does not ## On imaging Scrotal ultrasound with colour Doppler: in epididymitis the epididymis is enlarged with increased blood flow; spermatoceles are thin-walled cysts above the testis. ## Common problems - Epididymitis: painful swelling, often from an infection. - Cysts (spermatoceles), usually harmless. ## How it is diagnosed Examination; scrotal ultrasound; urine tests. ## Treatment - Antibiotics, rest and scrotal support for epididymitis. ## Clinical notes - Scarring after infection can block it and cause obstructive azoospermia; sperm can be retrieved surgically from it for assisted reproduction ## Anatomical variants - Appendix of the epididymis: a small vestigial remnant at its head that can twist and mimic torsion in boys ## Development Forms from the mesonephric (Wolffian) duct, with the efferent ductules from mesonephric tubules, under the influence of testosterone. ## Related conditions - [Epididymitis](https://durgical.com/en/conditions/epididymitis/) - [Male infertility](https://durgical.com/en/conditions/male-infertility/) ## Test yourself Think of the answer, then tap the question to see it. ## How does epididymitis differ clinically from testicular torsion? Epididymitis begins more gradually, often with fever and urinary symptoms, with tenderness at the back of the testis; Doppler ultrasound settles doubt. ## What are the usual causes of epididymitis by age? Younger sexually active men: chlamydia, gonorrhoea. Older men: bowel bacteria from urinary infection or obstruction. ## What is the Prehn sign, and how reliable is it? Lifting the scrotum eases pain in epididymitis but not in torsion; it is only a supporting sign. ## How is a spermatocele of the epididymis distinguished from a testicular mass? It arises from the head, is felt separate from and above the testis, and transilluminates; a testicular mass is treated as cancer until proven otherwise. [Add to my cards (4)](https://durgical.app/estudiar/?add=/en/anatomy/epididymis/) Educational information, not medical advice. For any symptom, see a health professional. ## Its names **Official Latin (TA2)** epididymis **Official Spanish (DeCS)** Epidídimo **English (TA2)** Epididymis ## Related - [Ductus deferens](https://durgical.com/en/anatomy/ductus-deferens/) - [Testes](https://durgical.com/en/anatomy/testis/) - [Testicular arteries](https://durgical.com/en/anatomy/testicular-artery-pelvis/) Sources: [Anatomy, Abdomen and Pelvis, Male Genitourinary Tract](https://www.ncbi.nlm.nih.gov/books/NBK562291/). ## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake Representative model, for educational purposes only. --- Source: https://durgical.com/en/anatomy/epididymis/ License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/anatomy/epididymis/