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.
The most effective form of reversible birth control after abstinence is an intra-uterine device , closely followed by hormonal contraception, which can come in the form of a pill, patch, implant, or insertable ring. IUDs have a failure rate of less than one percent in most controlled studies.