epididymis
Meaning of epididymis: The epididymis is a tightly coiled tube behind each testicle where sperm cells complete maturation and are stored before ejaculation.
Definition of epididymis
The epididymis is a narrow, tightly coiled tube attached to the back of each testicle, the male gland that produces sperm. Sperm cells produced within the testicle move into the epididymis, where they finish developing the ability to swim and are stored until they are needed.
The epididymis is divided into a head, body, and tail, with sperm gradually progressing through these regions as they mature over a period of time before being stored in the tail portion. From there, sperm pass into the vas deferens during ejaculation, the tube that carries them toward the urethra.
Because the epididymis sits so close to the testicle and shares much of its blood supply, inflammation or infection affecting one structure, such as epididymitis, can produce pain and swelling that is sometimes difficult to distinguish from a problem originating in the testicle itself.
Used in a sentence
Ultrasound was performed to evaluate the epididymis after the patient reported scrotal pain and swelling.
Good to know
Pain from epididymitis, inflammation of the epididymis, can closely resemble pain arising from the testicle itself, which is part of why a physical examination and sometimes imaging are used to determine which structure is actually affected.
Word origin
Where “epididymis” comes from
Formed from Greek epi-, meaning upon, and didymos, meaning twin, an early term for the testicle.