Epididymis - waiting loop for sperm

Few men (let alone women) know that the scrotum also houses the epididymis in addition to the testes. These are particularly important for the fertility of the man: Here, the sperm mature and wait for their "use".

What are the epididymides look like and what exactly are they doing?

The epididymis (epididymis, parorchis) belong together with penis and testicles to the male sex organs. Together with the testicles they sit in the scrotum (scrotum). Like a "C" they pull down on the back of the testicles from their upper end.

Each epididymis is about 5 cm long and contains in its interior up to 6m long, heavily looped tube, the epididymis (ductus epididymidis). The upper end, the head of the epididymis (Caput epididymidis), is connected to the testicle via many small channels, the seminiferous tubules (efferent ducts).

The middle section of the epididymis is called the body (corpus epididymidis). At the lower end follows the tail of the epididymis (Cauda epididymidis), which passes directly into the vas deferens. The vas deferens finally leads to the level of the prostate into the urethra. The entire epididymis is tightly connected to the testes via connective tissue (mesepididymis).

The inside of the epididymis is lined with a tissue (columnar epithelium) densely populated with small "eyelashes" (stereocilia) .Outside, seated on the epididymal head and body contractile myofibroblasts (connective tissue cells that contract), the tail is surrounded by smooth muscle cells This can cause the epididymis to contract and transport the sperm.

What is the function of the epididymis?

The immature spermatozoa from the testes reach the epididymis via the seminiferous tubules. The contact with the wall of the epididymis, the epididymal epithelium, is important for the later motility of the sperm. The epithelium secretes glycoproteins, molecules of sugar and protein. These are taken up by the surface of the sperm cells.

By contraction of the myofibroblasts, the sperm are transported over about 12 days from the head over the body to the epididymal tail, where they are finally stored. When the smooth muscles of the epididymal tail contract, the sperm are transported via the vas deferens to the urethra and finally released to the outside during ejaculation. Incidentally, the sperm cells reach their final fertility only in the female genital tract.

The so-called capacitation, which is triggered by the estrogen in the female body, enables the sperm to penetrate the sheath of the female ice.

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