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How many sperm cells are actually produced daily?

Bimek SLV Team | 13. November 2015

Two questions have plagued the minds of many men. How many sperm cells are created on a daily basis and where do they go when the Bimek SLV is closed. We’d like to take the time today to answer these questions in a simple and precise way.

Relevant reference materials state that semen is composed of 3 essential glandular secretions; 75% of ejaculation is built up by the seminal vesicles, they produce a secretion before the prostate, which in turn contributes 20% to the ejaculatory fluids. Only a maximum of 5% actually comes from the testicles, or more specifically the epididymis, and flows through the spermatic ducts.

But how can I be sure, without “extracting” the separate fluids from a seminal vesicle, a prostate or an epididymis? I simply can’t. I also don’t have a high performance liquid chromatography (HPLC) with which I can identify the many biochemical substances by type and quantity.

Although with the help of a microscope and a measuring scale I can determine the size of of a sperm cell. The egg-shaped head is approximately 5 µm long and 3 µm thick. The centre has a diameter of approximately 1 µm. Additionally there is the pointed tail, which gives the sperm cell a total length of about 50 µm or 1/20 mm. To figure out now how much volume a sperm cell takes up, the parts simply need to be calculated together; the head as an elongated rotational ellipsoid, the centre as a cylinder and the tail as an extremely pointed cone. I rendered the sperm cell with my Mega-CAD-Program in 3D and then calculated the volume. The results showed that a single sperm cell has a volume of approximately 27 µm³.

In order to comprehend just how small this is I searched for a reference object. I found what I was looking for in an object common to every household; the tiny ball of a ballpoint pen. I took one of these out of a pen and measured it with a sliding calliper; it had a diameter of 0,992 mm. I decided to round up to 1 mm and so calculated a volume of 0,5236 mm³. Divide this amount by the sperm cell’s 27 µm³ and you’ll be left with over 19 million. If you were to gather 19 million sperm cells in a way that there was absolutely no air present between them, they would then fit into a 1 mm ball of a ballpoint pen.

Now let’s take a look at the numbers in a semen analysis. According to WHO Norms and Standards an ejaculation should contain at least 39 million sperm cells. In order to achieve this concentration, a man has to remain abstinent for three to five days.

With this information I can determine that a man produces about a ballpoint pen ball-sized amount of pure sperm cells per day. If this amount is calculated over three months the volume will build up to an opened up paper clip with an 0,8mm wire diameter and a 90mm length. This amount has to be halved so that we know how many sperm cells each closed spermatic duct valve expels laterally, which are then biologically dismantled, or how many make into the ejaculatory fluids when the valves are opened.

Foto: Sperm von Iqbal Osman als Creative Commons auf Flickr