Oophorectomy

Oophorectomy is the surgical removal of the ovaries of a female animal. In the case of non-human animals, this is also called spaying. It is a form of sterilization.

The removal of the ovaries together with the Fallopian tubes is called salpingo-oophorectomy. Oophorectomy and salpingo-oophorectomy are not common forms of birth control in humans; more usual is tubal ligation, in which the Fallopian tubes are blocked but the ovaries remain intact.

In humans, oophorectomy is most usually performed together with a hysterectomy - the removal of the uterus. Its use in a hysterectomy when there are no other health problems is somewhat controversial.

In animals, spaying involves an invasive removal of the ovaries, but rarely has major complications; the superstition that it causes weight gain is not based on fact. Spaying is especially important for certain animals that require the ovum to be released at a certain interval (called estrus or "heat"), such as cats and dogs. If the cell is not released during these animal's heat, it can cause severe medical problems that can be averted by spaying or partnering the animal with a male.

Oophorectomy is sometimes referred to as castration, but that term is most often used to mean the removal of a male animal's testicles.

See also


Sputnik program


The Sputnik program was a series of unmanned space missions launched by the Soviet Union in the late 1950s to demonstrate the viability of artificial satellites. The name "Sputnik" ("Спутник") comes from Russian where it means "satellite" or "fellow traveller".

Sputnik 1 was launched on October 4, 1957. See that page for mission details.

Sputnik 2 was launched some months later, and carried the first living passenger, a dog named Laika. The mission planners did not provide for the safe return of the spacecraft or its passenger, making Laika the first space casualty.

The first attempt to launch Sputnik 3 on February 3, 1958 failed, but the second on May 15 succeeded, and it carried a large array of instruments for geophysical research. Its tape recorder failed, however, making it unable to measure the Van Allen radiation belts.

Sputnik 4 was launched into orbit two years later on May 15, 1960.

Sputnik 5 was launched into orbit on August 19, 1960 with the dogs Belka and Strelka (Russian for "Squirrel", or more likely "Whitey" from Russian "belyj", which means "white", and "Little Arrow"), 40 mice, 2 rats and a variety of plants on-board. The spacecraft returned to earth the next day and all animals were recovered safely.

All Sputniks were carried to orbit by the R.7 launch vehicle, originally designed to carry ballistic warheads.

The surprise launch of Sputnik 1, coupled with the spectacular failure of the first two Project Vanguard launch attempts, shocked the United States, which responded with a number of early satellite launches including Explorer I, Project SCORE, Advanced Research Projects Agency and Courier 1B. Sputnik also led to the creation of NASA and major increases in U.S. Government spending on scientific research and education. See: Sputnik crisis.



Last updated: 02-09-2005 23:57:34