Quick Answer. The function of the cartilaginous rings of the trachea is to stabilize the trachea and keep it rigid while allowing the trachea to expand and lengthen when the person breathes. If the trachea was not supported in this way, it would simply collapse because of the pressure of the chest.
1 The Pill. The pill is the common name for oral contraception. It's one of the safest, most effective, and popular methods of birth control. The pill is made up of synthetic forms of hormones that naturally occur in a female's body - progestin and estrogen.
Birth control pills usually contain one or two hormones. These hormones prevent egg release from the ovaries. It also causes changes in the cervical mucus and uterine lining which may make it more difficult for sperm to fertilize an egg. Birth control comes in many forms, but is commonly prescribed in pill form. Patches and injections are alternatives to pills. Common hormone combinations include estrogen / progestin / folate combinations, estrogen / progestin / iron combinations, estrogen / progestin combinations, and progestins.