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.
There are two main kinds of birth control pills â combination birth control pills, which contain estrogen and progestin, and the minipill, which contains only progestin. Combination birth control pills come in different mixtures of active and inactive pills, depending on how frequently you want to have periods: