What is sperm made of? The answer may surprise you.
The first and most common misconception that needs to be addressed is that semen and semen are not the same. Although the two terms are sometimes discussed interchangeably, semen and semen are different. Sperm are reproductive cells that live and travel in semen. Semen is a mixture of fluids that contains semen, but most of semen is made up of more than 200 individual proteins, as well as vitamins and minerals, including vitamin C, calcium, chlorine, citric acid, fructose, lactic acid, magnesium, nitrogen, phosphorus, potassium, sodium, vitamin B12 and zinc. That’s a lot of stuff to pack into a few milliliters of liquid.
The reason semen contains so many of these compounds is mainly to support sperm. The proteins, minerals, fatty acids, and other compounds in semen are primarily responsible for providing the sperm with the energy it needs to move and penetrate an egg, and this includes the egg’s natural resistance to the sperm. Sperm that enters another reproductive system is considered a foreign substance, and so the body that enters it will try to reject it. One element of sperm, lipids called prostaglandins, helps sperm evade detection by the other body. But this is only a small part, which is actually a complex mixture of fluids produced by different organs.
How sperm is made
Sperm production begins with the production of sperm in the testicles. Once the sperm is produced, it is stored in the epididymis (a series of ducts behind the testicles) and matures there for at least a day. From the epididymis, sperm travels to the seminal vesicles, prostate, and bulbourethral glands, picking up the various fluids that make up semen along the way.
While semen may be the most infamous, it only makes up 1 to 5% of semen. While that percentage may seem small, sperm is microscopic, and even at such a small total percentage, there can still be hundreds of millions of sperm in one average ejaculation. The exact amount of semen in each ejaculation depends on several factors, such as age, weight, diet and exercise.
Most of what semen contains (about 70%) comes from the next step in the production process, the seminal vesicles. The seminal vesicles are a pair of glands below the bladder. The vesicles produce a fluid that contains nutrients such as ascorbic acid (also known as vitamin C), amino acids, phosphorus, potassium and more. These minerals, acids and proteins help keep sperm healthy. However, most of the liquid consists of fructose, a form of sugar. Sugar is fuel and its purpose in semen is to provide sperm with the fuel it needs to travel through the body.
The next step in the process is the prostate. The prostate gland is responsible for the production of fluid that makes up about 25% of semen. Like the fluid produced by the seminal vesicles, this fluid consists mainly of nutrients, such as citric acid, calcium, zinc, magnesium and acid phosphate. Zinc is the most abundant mineral in this fluid because it is responsible for stabilizing the sperm’s DNA. Zinc is also responsible for the color and taste of semen.
The prostate also contributes to a protein in semen known as PSA. This protein is responsible for breaking down semen into a thinner fluid after ejaculation. Semen is naturally thick, so it can adhere better to the cervix when ejaculation occurs in the vagina. After the semen is released, PSA helps the seminal fluid liquefy over time, releasing the semen.
These three elements (semen and fluids from the seminal vesicles and prostate gland) make up the bulk of semen, but there is one other fluid that is found in small amounts (usually no more than 1% of semen). This fluid comes from the bulbourethral glands, which are located near the base of the penis. These glands are responsible for producing the fluid commonly known as precum. Precum is produced as a result of sexual arousal, and this mucus is responsible for lubricating the glans and removing residual urine from the urethra in preparation for ejaculation.
In discussions about safer sex practices, it is often noted that precum does not contain sperm. This is technically true, as we just explained. Precum is a separate substance that does contain a small amount of semen, which contains sperm, but precum itself does not contain sperm. However, because precum follows the same routes as semen, it can pick up other elements that make up semen along the way, including semen. The likelihood of viable sperm being mixed with precum largely depends on how much time has passed since the most recent ejaculation. As a rule, however, it is important to remember that pre-cum is not always semen-free and can pose a risk of pregnancy, and that regardless of whether semen is present, pre-cum is still a sexual fluid that can transmit sexually transmitted diseases and infections .
Practicing safer sex includes a variety of different ideas and practices, such as getting regular STD testing. Now that you know what semen is made of and how it is produced, you are better informed, which is another important part of safer sex.