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.
Thursday is the day of the week between Wednesday and Friday. Its name is derived from the name of the Norse/Germanic god Thor.
By some conventions (see ISO 8601), the Thursdays of a year determine the week numbering: week 1 is defined as the week that contains the first Thursday of the year, and so on.
In the popular rhyme, "Thursday's Child has far to go".
In the United Kingdom, elections are traditionally held on Thursdays. This was to ensure a high turnout, as people would have spent their previous weeks wages, paid the previous Friday.
In The Hitchhiker's Guide to the Galaxy by Douglas Adams, the character Arthur Dent says "This must be Thursday. I could never get the hang of Thursdays". A few minutes later the planet Earth is destroyed.
Thursday is the name of a rock band on Island Records from New Brunswick, NJ, USA.
Thursday is also the first name of the main character of Jasper Fforde's popular books: The Eyre Affair, Lost In A Good Book, The Well of Lost Plots , and Something Rotten . Her full name is Thursday Next, playing on the British phrase. Her mother's name is Wednesday.
Thursday is also the name of a movie directed by Skip Woods in 1998, starring Thomas Jane and Aaron Eckhart.
Thursday is also the name of an emo/hardcore band from the US; see Thursday (band).