Fertility, Male

Hormones are always at work in a man's body, preparing him to be able to become a father. The pituitary gland in the brain sends a hormone, called follicle-stimulating hormone, (FSH) to the testicles, signaling them to produce sperm, the male reproductive cells. After sperm are produced in the testicles, they travel through a tube called the vas deferens to the seminal vesicle, which holds the mature sperm. The prostate gland makes seminal fluid, the fluid which transports the sperm in the urethra. The urethra is a tube extending from the bladder, through the prostate, and through the penis to the outside of the man's body. During sexual activity, vessels in the penis fill with blood, causing the penis to become firm and erect (the male erection.) The prostate gland fills with as much seminal fluid as it can comfortably hold, after which it contracts. The contractions draw sperm from the seminal vesicle. Seminal fluid mixed with sperm is called semen. The contractions of the prostate gland force the semen through the urethra and out the tip of the penis (ejaculation).The ejaculate (semen) is a teaspoon to a tablespoon of thick milky liquid and contains millions of microscopic sperm. Even though the urethra transports both urine and semen out through the penis, when a man has an erection a valve closes between the prostate gland and the bladder to prevent urine from being released when semen is ejaculated. Practically speaking, this means that (thankfully) a man cannot urinate and ejaculate at the same time. During sexual relations, when ejaculation has deposited the sperm in the woman's vagina, the sperm swim up the vagina to the uterus. They swim in the cervical mucus that is produced during the fertile time of a woman's cycle of fertility. The secretions of the vagina are normally acidic to protect women from infections. The acidic secretions of the vagina are hostile to sperm. But the fertile mucus is alkaline and protects the sperm from the acidic environment of the vagina. It also filters out imperfect sperm and guides the healthy sperm up into the uterus. >From there the sperm swim into the fallopian tubes. Testosterone, the male hormone, can cause a man to feel competitive, aggressive, and very interested in women. However, successful men everywhere have learned to harness their hormonal energy to fulfill their life goals, rather than allowing their hormones to direct their lives.