Parts of the Reproductive System
Male Reproductive System
The gonads, or sex organs, of the male reproductive system are the testicles, also known as the testes. The testes produce sperm, the male sex cells, and they release testosterone, the male sex hormone. The scrotum is a skin pouch that holds the testicles outside of the body in the groin area between the legs. The testes are outside of the body because developing sperm need to be kept at a temperature lower than the body's normal temperature of 98.6°F.
The male reproductive system also consists of long series of tubes that carry sperm from the testicles where they are produced, to the penis where they are ejaculated. The first part of these tubes is the epididymis, which surrounds the testes and connects to the vas deferens. It is an extremely thin, coiled tube that would measure about 20 feet long if it were straightened. The sperm enter the epididymis from the testicles to reach the vas deferens.
There are two vas deferens, one for each testis. The vas deferens is a long tube that ascends from the testes, goes up the scrotum, and around the urinary bladder. The ejaculatory ducts then connect the vas deferens to the urethra.
In the urethra, the sperm are mixed with a viscous fluid called seminal fluid. Seminal fluid is secreted by the prostate and bulbourethral glands and promotes the survival and movement of the sperm. Together, the sperm and seminal fluids are known as semen, which flows out of the male’s body through his urethra.
Female Reproductive System
The gonads of the female reproductive system are the ovaries. There are two ovaries, each about the size of an almond. One is located on either side of the uterus in the lower abdomen. They produce the female reproductive cells, called ova (plural for ovum) or eggs, and secrete the sex hormones, estrogen and progesterone. Each ovary is associated with a fallopian tube, which is about 4 inches long, that can facilitate the movement of the egg into the uterus.
The uterus is located in the lower abdomen between the urinary bladder and the rectum. In a woman who has never been pregnant, the uterus, also known as the womb, is 3 inches long, about the size of a pear. If an egg is fertilized by a sperm, the fertilized egg may be implanted into the uterus and remain there as it grows. The uterus provides a warm, protective space the entire time the fetus develops into a baby.
The uterus is connected to the exterior of the body by the vagina. The vagina is a tube, about 3 inches long, also located between the bladder and the rectum.
The mammary glands, or breasts, are also considered part of the female reproductive system. Once a woman has given birth, the hormone prolactin stimulates the mammary glands to lactate, or produce milk.