Fertility |
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Male Reproduction
As with female fertility, male reproduction is hormonally driven -- requiring a normally functioning hypothalamus and pituitary gland to support sperm production, called spermatogenesis. The testes must be capable of response to this hormonal stimulus. In addition, there must be an intact ductal system to transport sperm to the urethra.
The male external genitals consist of the scrotum, which houses the testes and associated ductal systems (the epididymis and vas deferens) and the penis. The testes are covered by a tough fibrous layer called the tunica albuginea which divides the testes into lobules. Each of the 200 to 300 lobules contains one to three long and tightly coiled seminiferous tubules, within which sperm production occurs.
In contrast to female eggs, sperm are continually produced throughout a man's lifetime. During spermatogenesis and transport through the male reproductive tract, the male spermatozoa is transformed into a highly specialized cell with its own motility and enzymatic capacity to penetrate the egg. Epididymal function must be normal and the accessory glands must be functional to produce normal seminal plasma. An intact nervous system also is required to permit penile erection and normal ejaculation.
Male infertility can be divided into problems with:
- Ejaculation and erection
- The fine, small reproductive tract ducts
- Sperm production
Problem with sperm production is by far the most common of the three and can be detected during semen analysis. There are many causes of abnormal sperm production including:
- Varicocele
- Genetic problems
- Infections
- Exposures to heat or toxic chemicals
- Drugs and medications
- Hormonal imbalance
More Information:
Reviewed by health care specialists at UCSF Medical Center.
Last updated May 8, 2007
This information is for educational purposes only and is not intended to replace the advice of your doctor or health care provider. We encourage you to discuss with your doctor any questions or concerns you may have.
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