What happens to sperm that isn't ejaculated?
What happens to all the sperm that isn’t ejaculated, where does it go and is it still healthy?
Chris - Yes. It's a very good question; the testes make sperm at about 5000 sperm a second at peak. They put these sperm into what are called the seminal vesicles, which are structures up inside the body, for storage until it is needed. This is because sperm are best made at a slightly lower temperature than body tempearture, which is why the testes are outside the body, because the temperature there is about one degree lower. But sperm are best stored and kept viable inside the body at "body temperature" - 37 degrees C. So this is why they're moved to the seminal vesicles. There they're nourished and have various components of semen added, which has got fructose, minerals and other sugars which keep the sperm healthy.
The sperm can survive there for quite a long period of time inside the body; but eventually they will senesce and they will age. And of course all the things that you take into your body, cigarette smoke, other toxins and things will damage the sperm potentially. So they have a sort of recycle time. And sperm that have reached their sell-by-date get broken down in the same way that, let's say, blood cells get broken down. And basically any of the nutrients and goodies in the sperm just get recycled back inside the body, and new sperm are produced to make up for the shortage.
Helen: - So it's a kind of continual, sort of, replacement, really.
Chris: - Exactly. Those that don't leave the body eventually break down, and their components are recycled.