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.
What is the birth control shot? The birth control shot is an injection of synthetic progesterone (progestin) that's given to women every three months to prevent pregnancy. The shot that's currently available in the United States is a form of progestin known as DMPA, which stands for depot medroxyprogesterone acetate.