Читать книгу Getting Pregnant For Dummies - Sharon Perkins - Страница 55

Testicles are the sperm production and warehouse site. Here, as in many other places on the human body, nature has been generous and given two of the same body part (testicles, in this instance), in case something happens to one. Testicles first develop inside the abdomen and gradually descend outside the body by the time a baby boy is born. At birth, about 4 in 100 boys have undescended testicles, properly called cryptorchidism. Testicles need to be kept a few degrees cooler than 98 degrees for sperm to develop properly, so to prevent future infertility, doctors usually recommend surgery to lower the testicles outside the body as soon as the baby is a year old.

The testicles are contained in a pouch of skin called the scrotum. In about 80 percent of men, the left testicle is bigger and hangs lower. Sometimes the scrotum is abnormally large, which can be caused by a hydrocele (a collection of fluid inside the scrotum), or by a varicocele (dilated or varicose veins in the scrotum). These conditions can be surgically corrected. If left alone, they can raise the temperature of the testes and may cause infertility.

Sperm are produced every day, but it takes about 70 days for the new sperm to fully mature. Sperm production starts in the testes. FSH and LH, the same hormones that develop eggs, are needed to begin sperm production. LH stimulates production of testosterone, another male hormone. The sperm mature in the epididymis and travel through the vas deferens up to the seminal vesicle and the prostate, where they’re bathed in the fluid known as semen. They’re then ejaculated through the urethra during male orgasm.