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 are a very popular form of birth control because they are affordable, convenient and effective. Depo-Provera is another type of hormonal birth control. It is given by injection every three months and one injection prevents you from getting pregnant for up to 13 weeks.