Human reproduction

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Further information: Human reproductive system

The human male[edit]

For more details on this topic, see Human male reproductive system.
Lao students study a display about the human reproductive system. Exhibits such as this are rare in many less-developed countries, such as Laos. This event was held by Big Brother Mouse, a literacy and education project, which added Lao explanations to a commercially-available set of panels that were printed with English.

The male reproductive system contains two main divisions: the testes where sperm are produced, and the penis. In humans, both of these organs are outside the abdominal cavity. Having the testes outside the abdomen facilitates temperature regulation of the sperm, which require specific temperatures to survive about 2-3 °C less than the normal body temperature i.e. 37°C. In particular, the extraperitoneal location of the testes may result in a 2-fold reduction in the heat-induced contribution to the spontaneous mutation rate in male germinal tissues compared to tissues at 37°C.[1] If the testicles remain too close to the body, it is likely that the increase in temperature will harm the spermatozoa formation, making conception more difficult. This is why the testes are carried in an external pouch viz. scrotum rather than within the abdomen; they normally remain slightly cooler than body temperature, facilitating sperm production.

The human female[edit]

For more details on this topic, see Human female reproductive system.

The female reproductive system likewise contains two main divisions: the vagina and uterus, which will receive the semen, and the ovaries, which produces the ova. The vagina is attached to the uterus through the cervix, while the uterus is attached to the ovaries via the Fallopian tubes. At certain intervals, the ovaries release an ovum, which passes through the fallopian tube into the uterus.

The fertilization of the ovum with the sperm occurs at the ampullary-isthimic junction only. That is why not all intercourse results in pregnancy. The ovum meets with Spermatozoon, a sperm may penetrate and merge with the egg, fertilizing it with the help of certain hydrolytic enzymes present in the acrosome. The fertilization usually occurs in the oviducts, but can happen in the uterus itself. The zygote then becomes implanted in the lining of the uterus, where it begins the processes of embryogenesis and morphogenesis. When the fetus is developed enough to survive outside the womb, the cervix dilates and contractions of the uterus propel it through the birth canal, which is the vagina.



Human reproduction begins with sexual intercourse, followed by nine months of pregnancy before childbirth. Many years of parental care are required before a human child becomes independent. Pregnancy can be avoided with the use of contraceptives such as condoms and IUD's.

Sexual intercourse[edit]

Main article: Sexual intercourse

Human reproduction takes place as internal fertilisation by sexual intercourse. During this process, the erect penis of the male is inserted into the female's vagina, and then either partner initiates rhythmic pelvic thrusts until the male ejaculates semen, which contains sperm, into the vaginal canal. This process is also known as "coitus", "mating", "having sex", or, euphemistically, "making love". The sperm travels through the vagina and cervix into the uterus or Fallopian tubes for fertilization of the ovum. Upon fertilization and implantation, gestation of the fetus then occurs within the female's uterus.


Main article: Pregnancy



Main article: Childbirth

Once the fetus is sufficiently developed, chemical signals begin the process of birth, which begins with the fetus being pushed out of the birthing canal. The newborn, which is called an Infant in humans, should typically begin respiration on its own shortly after birth. Not long after, the placenta eventually falls off on its own. The person assisting the birth may also sever the umbilical cord.

Parental care[edit]

Main article: Parenting

Human babies are nearly helpless and require high levels of parental care for many years. One important type of parental care is nursing – feeding the baby milk from the mother's mammary glands in her breasts.[2]

Political and social[edit]

There are groups promoting more human reproduction and those who think reproduction ought to be limited. Natalism promotes reproduction, while anti-natalism promotes birth control as a solution to overpopulation and its effects. One notable anti-natalist group, is the so-called "Voluntary Human Extinction Movement", which advocates the voluntary, but complete elimination of the human species from Earth's planetary biosphere, in order to effect the recovery and preservation of the planet's natural environment, as a whole.

See also[edit]


  1. ^ Baltz RH, Bingham PM, Drake JW (1976). Heat mutagenesis in bacteriophage T4: The transition pathway. Proc. Nat. Acad. Sci. USA 73(4): 1269-1273. PMID 4797