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.
The law of the United States is derived from the common law of England, which was in force at the time of the Revolutionary War. However, the supreme law of the land in the United States is the United States Constitution and, per the Constitution, treaties to which the U.S. is a party. These form the basis for federal laws under the federal constitution in the United States circumscribing the boundaries of the jurisdiction of federal law and the laws in the fifty U.S. states and territories.
Federal law in the United States originates with the constitution, which gives Congress the power to enact statutes for certain limited purposes like regulating commerce. Nearly all statutes have been codified in the United States Code. Many statutes give executive branch agencies the power to create regulations, which are published in the Code of Federal Regulations and also carry the force of law. Many lawsuits turn on the meaning of a federal statute or regulation, and judicial interpretations of such meaning carry legal force under the principle of stare decisis.
As for state law in the United States, American states are separate sovereigns with their own constitutions and retain the power to make laws covering anything not preempted by the federal Constitution or federal statutes. Although nearly all of them started with the same English common law base, the passage of time has resulted in enormous diversity in the laws of the fifty states.
Efforts by various organizations at creating "uniform" state laws have been only partially successful. The most famous examples are the Uniform Commercial Code and the Model Penal Code .
Furthermore, states have delegated lawmaking powers to a staggering number of agencies, counties, cities, and special district s. And all the state constitutions, statutes and regulations are subject to judicial interpretation like their federal counterparts.
Thus, at any given time, the average American citizen is subject to the rules and regulations of several dozen different agencies, depending upon one's current location and behavior.
Unlike the rest of the country, state law in Louisiana is based on the Napoleonic Code, inherited from its time as a French colony. Puerto Rico is also a civil law jurisdiction. However, the criminal law of both jurisdictions has been necessarily modified by common law influences and the supremacy of the federal Constitution.
California is a common law jurisdiction with a few features borrowed from the civil law. For example, it has a community property system for the property of married persons, and its statutes have long been codified into a complex system of named codes (Health and Safety Code, Vehicle Code, and so on).