Condom, male: The male condom is a sheath placed over the erect penis before penetration, preventing pregnancy by blocking the passage of sperm. It is a barrier method of contraception.
A condom can be used only once.
Although some condoms have spermicide added (the spermicide is usually nonoxynol-9 in the United States) to kill sperm, spermicide has not been scientifically shown to provide additional contraceptive protection over a condom alone.
Because they act as a mechanical barrier, condoms prevent direct vaginal contact with semen, infectious genital secretions, and genital sores and discharges.
Most condoms are made from latex rubber, while a small percentage are made from lamb intestines (sometimes called “lambskin” condoms). Condoms made from polyurethane have been marketed in the United States since 1994.
Except for abstinence, latex condoms are the most effective method for reducing the risk of infection from the viruses that cause AIDS, other HIV-related illnesses, and other sexually transmitted diseases (STDs). It does not protect against transmission of the human papilloma virus (HPV).
Some condoms are prelubricated. These lubricants do not provide more birth control or STD protection. Non-oil-based lubricants, such as water or K-Y jelly, can be used with latex or lambskin condoms, but oil-based lubricants, such as petroleum jelly (Vaseline), lotions, or massage or baby oil, should not be used because they can weaken the material.
- Conduction system, cardiac
Conduction system, cardiac: The electrical conduction system that controls the heart rate. This system generates electrical impulses and conducts them throughout the muscle of the heart, stimulating the heart to contract and pump blood. Among the major elements in the cardiac conduction system are the sinus node, atrioventricular node, and the autonomic nervous system. The […]
Condyloma: Wartlike growths around the anus, vulva, or glans penis. There are three major types of condyloma, each of which is sexually transmitted: condyloma acuminatum (warts around the vulva), condyloma latum (a form of secondary syphilis), and condyloma subcutaneum (also known as molluscum contagiosum).
- Condyloma latum
Condyloma latum: A form of the secondary stage of syphilis, characterized by wartlike growths around the anus.
- Condyloma subcutaneum
Condyloma subcutaneum: A sexually transmitted disorder characterized by wartlike growths around the anus and genitals that is caused by the virus poxvirus. Also known as molluscum contagiosum.
Cone: A type of specialized light-sensitive cell (photoreceptor) in the retina of the eye that provides color vision and sharp central vision. By contrast, the rods are the retinal photoreceptors that provide side vision and the ability to see objects in dim light (night vision).