Millions of sperm cells are produced each day in a system of tubes called the seminiferous tubules in the testicles. Hormones help these simple cells transform into the tadpole-like sperm with its head and tail that is able to fertilise an egg.
Once sperm mature, they move into the epididymis where they remain until sexual stimulation launches them toward the prostate gland and seminal vesicles to combine with fluids and become semen. The whole process takes about 74 days.
How does it happen?
Sperm cells develop in a system of tubes called the seminiferous tubules inside your testicles. These tubes open into a long, coiled structure called the epididymis. Mature sperm are stored in the epididymis until they are ready to leave the body. Sperm typically die within minutes outside the male body, but they can live for three to five days inside a woman’s body (depending on whether they reach the egg). If a man doesn’t ejaculate, sperm will break down and the body will reabsorb them. The sperm production process is known as spermatogenesis, and it takes about 70 days from the start of sperm cell development to ejaculation.
The process of sperm production is complex, but it starts with immature sperm cells called spermatocytes. These sperm cells multiply, forming more mature sperm cells known as spermatozoa. Eventually, these sperm cells mature enough to leave the testicles through the vas deferens, a long tube that extends from the epididymis to the prostate and seminal vesicles. The sperm cells are then mixed with seminal fluid, which provides nutrients and protection for the sperm as they travel to the female reproductive tract.
Most men produce many millions of sperm cells every day. If a man’s testicles are functioning normally, the sperm will usually meet an egg and fertilize it within 24 hours of ovulation. Afterward, the fertilized egg implants into the uterus.
Testicular development
Sperm cells are created in a process called spermatogenesis, which occurs in a man’s testicles. This begins when stem cells in the seminiferous tubules, which are small tubes within the testicles, start to divide and transform into sperm. This takes about 64 days to complete. The next step is for the sperm to mature, which requires a special gland in the testicles called the epididymis. This is where sperm are stored until ejaculation. During this time, the sperm also gain motility, which allows them to move when they are released into seminal fluid (semen) during ejaculation.
Once the sperm have gained their motility, they are ready to travel through the female body for fertilization. This is where they have the best chance of success, as sperm can live for five days inside a woman’s reproductive tract. During this time, they will be nourished by the woman’s cervical mucus, which will help them swim to the egg.
The average man can produce millions of sperm in a day. However, this number can decrease as a man gets older, due to changes in hormones like FSH and LH. In addition, a man’s sperm count can be affected by a variety of health and lifestyle factors. Frozen sperm that is cryogenically frozen with liquid nitrogen can last years after being thawed, but this isn’t an option for people who need sperm immediately.
Epididymal development
During puberty, your body makes millions of simple cells that develop into mature sperm. These sperm move from the testicles into a system of tubes called the seminiferous tubules. These tubes then join the epididymis, which is a worm-like appendage that sits to the side and in back of each testicle. The sperm then travels through the epididymis, which stores them until you want to use them.
The epididymal epithelium produces a wide variety of antioxidant proteins that help protect the sperm from oxidative damage during their journey from the testis to the vas deferens and ductus deferens. These proteins include catalase, glutathione peroxidases, superoxide dismutases, and thioredoxin reductase. A shortage of these protective agents reduces sperm quality and can contribute to male infertility.
Once sperm reach the epididymis, sexual stimulation causes them to move out into the vas deferens. This long, thick-walled tube takes them toward a cavity in the pelvis, where it joins with fluid from the seminal vesicles and prostate gland to form semen. It’s this semen that is released during orgasm or when you ejaculate. In normal men, the entire sperm production and maturation cycle takes between 70 and 75 days.
Sperm movement
Once sperm have been created, they are stored in a long tube-like structure called the epididymis in the scrotum. Hormones from FSH and LH help sperm develop into their tadpole-like shape and then move to the epididymis, where they will stay until they are ready to be released. This process of sperm production takes about 70 days from start to finish.
During this time, the sperm cells must become motile. This is a critical step because it allows the sperm to move toward and fertilize an egg. Motility is measured by the percentage of sperm that are moving in a straight path, rather than twitching or swimming around in circles. A normal percentage is above 32%.
Doctors also look at progressive motility, which measures how quickly sperm can change direction. A high percentage of sperm with this ability means that they are more likely to successfully fertilize an egg.
Once sperm have reached the epididymis, they are released into the vas deferens. This muscular tube carries them from the testicles to the prostate gland and then to the urethra. Once there, the sperm is mixed with seminal fluid secreted by the prostate gland to produce semen. This fluid is then ejaculated from the penis through an orgasm or during masturbation. The sperm then swims down the fallopian tubes and meets an egg to create a baby.
