Summary

Summary

The reproductive organs produce sex cells and hormones, sustain them, or transport them. The primary­ male sex organs are the testes, which pro-duce sperm cells and male sex hormones. A sperm cell consists of a head, midpiece, and tail. The male internal accessory organs include the epididymides, ductus ­deferentia, seminal vesicles, prostate gland, and bulbourethral glands. The male external repro-ductive organs include the scrotum, testes, and penis. Orgasm is the culmination of sexual stimulation.

Emission and ejaculation accompany male orgasm. Male reproductive functions are controlled by hypo-thalamic and pituitary hormones, FSH, and LH. Male sex hormones are called androgens, with testosterone the most important.

The primary female sex organs are the ovaries, which produce female sex cells and sex hormones. Ovulation is the release of a secondary oocyte from an ovary. The release of an oocyte involves structures, including the primordial follicles, and the processes of oogenesis and follicle maturation. The female internal accessory organs include the uterine tubes, uterus, and vagina. The female external reproductive organs include the labia majora, labia minora, clitoris, and vestibule. The hypothalamus, anterior pituitary gland, and ovaries secrete hormones that control sex cell maturation. They also control development and maintenance of female secondary sex characteristic and changes that occur during the monthly repro-ductive cycle. The most important female sex hor-mones are estrogens and progesterone. The female reproductive cycle is approximately 28 days in length. A female’s reproductive life is shorter than that of a male, beginning with menarche during puberty and ending with menopause.

Birth control is voluntary regulation of the produc-tion of offspring and when they are conceived. It usu-ally involves some method of contraception. Popular methods include coitus interruptus, the rhythm method, condoms, diaphragms, cervical caps, chemical barriers, combined hormone contraceptives, injectable contra-ception, IUDs, and surgery. Some forms of contracep-tion also protect against STIs. STIs often do not show symptoms until they have become very serious. Most reproductive diseases are caused by STIs. Chlamydia,­ trichomoniasis, HIV, gonorrhea, and syphilis are exam-ples of diseases that may be transmitted sexually. Pelvic inflammatory disease may be a complication of gon-orrhea or chlamydia and can lead to female sterility or ectopic pregnancy. Genital herpes is a common STI that may be present in 25% to 50% of all American adults. Genital warts are caused by HPV, which is linked to the development of cervical cancer. The end of reproductive life in women is signaled by menopause, but in men this does not occur as significantly, with some men able to father children into their later years.