Although many people have some knowledge about sperm, there are also many misconceptions about male gametes. This article will separate some interesting sperm facts from some common myths.
The following are four confirmed sperm-related facts:
Sperm and Semen are Not the Same
Sperm cells are male gametes. The job of these cells is to find a female gamete to fuse with, for unassisted reproduction. In this process, semen is released through the penis and enters the vagina. This discharge is known as ejaculation.
When this happens, the sperm enters the fluid produced by the male genitalia. This mixture of semen and fluid is called semen.
Sperm Takes a Long Time to Produce
The process of producing sperm is called spermatogenesis.
The testes, the male reproductive organs, produce sperm. Inside the testicles are small tubes called seminiferous tubules.
Spermatogenesis consists of several stages:
- Hormones enter the tubes that house the germ cells.
- Germ cells divide and change many times with the help of hormones like testosterone.
- They gradually transform into spermatozoa, which are young sperm cells.
- They grow and mature in sperm, each with a head and a tail-like tadpole.
Researchers estimate that this process takes about 74 days.
The sperm then travel through the epididymis, a tube behind the testicles, before ending up in the vas deferens, another tube that connects to the ejaculatory duct.
Lifestyle Choices can Affect Sperm Count
The number or concentration of sperm in the ejaculate sample usually determines the sperm count. There is some evidence that lifestyle choices can affect this number.
For example, one large study found a link between smoking and low sperm count. There is also evidence that dietary changes may play a role. For example, some research suggests that increased levels of vitamin D can boost sperm production.
Sperm Count May Vary with Location and Ethnicity
Scientists know that sperm counts are declining in many Western countries. According to one study, between 1973 and 2011 in North America, Europe, New Zealand and Australia, average sperm count decreased by 59.3%.
Researchers don’t yet understand what causes the decline, though it may be due to lifestyle changes.
There is also some evidence of a link between ethnicity and differences in sperm production. One study notes the following differences in sperm counts among Latino, white, and Chinese men:
- Chinese males produced 70–173 million sperm cells per day.
- Latinx males produced 231–398 million sperm cells per day.
- White males produced 193–318 million sperm cells per day.
Sperm Myths
The following are four sperm-related myths:
Briefs are Bad for Sperm Count
Some people believe that wearing tight underwear can significantly lower a man’s sperm count. However, scientific evidence suggests that this is an overstatement.
A recent study showed that men who wear boxers have a 17% higher sperm count than those who wear briefs. However, the study authors acknowledge that these results may not be reliable, as their research relied on participants’ self-reporting and recall, among other factors.
Pre-Ejaculate Cannot Lead to Pregnancy
Pre-ejaculation is when the penis releases a small amount of fluid before ejaculation. This fluid is known as pre-ejaculate.
Although pre-ejaculation does not act to collect sperm in the vagina, it can pick up live sperm cells as they travel through the penis. For example, one study found healthy sperm within 16.7 percent of pre-ejaculatory samples.
For this reason, it is very unlikely that pre-ejaculatory exposure could lead to pregnancy.
Sperm Production Doesn’t Change with Age
Many people believe that older men can produce sperm as well as younger men. However, this is a myth. Although sperm production continues throughout most men’s lives, sperm quality declines with age.
For example, research shows that sperm from older men are more likely to cause genetic mutations in their offspring than sperm from younger men.
Sperm Cells are Great Swimmers
A man’s body makes millions of sperm cells every day. In humans and other animals, sperm can move using a tail or flagellum. This allows them to travel through the female reproductive organs to the egg.
This may give the impression that millions of sperm end up in a close race to the egg, but this is not true. Many sperm cannot swim at all, or only very poorly. In fact, researchers know that many sperm cells move passively toward the egg.