Function of epididymus

go ahead and worry about it

The epididymis is sort of like Kindergarten for sperm; it’s a transitional space where sperm mature, grow then leave to make their mark in the world, primarily by populating it. The epididymis is a coiled tube of crazy length, about 20 feet, surrounded by tissue and blood vessels. It is found inside the scrotum behind the testis where it receives sperm and holds them until they mature. The end of the epididymis delivers the sperm to the vas deferens which runs from the pelvis to the penis. The tube absorbs fluids and nutrients needed to grow and develop the sperm.

The testis manufactures the sperm then boots it out to the epididymis. At this point, they are pretty worthless except for the valuable cargo (DNA) that they carry. These immature sperm are immobile and not fully formed. They will grow and develop as they move through the 20 feet of the epididymis getting nourished along the way.

The sperm will be able to move forward when the protein CatSper becomes activated. CatSper is found in the tail and allows calcium ions to flow in. This creates a contraction of fibrous proteins and the beating motion of the tail which propels it forward.

Smooth muscle cells surrounding the walls of the epididymal duct contract and help carry along the sperm by providing a slick surface. Once mature and ready to go, the sperm approaches the vas deferens arises, kind of like college for sperm. The seminal vesicle, which produces nourishing fluid for sperm, joins the vas deferens to create the ejaculatory duct (I’m envisioning a beer-bong; that was what nourished the college boys I knew). The ejaculatory ducts opens into the urethra, which originates in the bladder. That passes through the prostate and enters the penis.

All kinds of things can screw up the function of the epididymis: bacterial infection, sexually transmitted disease, urinary infection. These infections can threaten fertility, but they can also be treated with early intervention.


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