The respiratory system is divided into four components: the upper respiratory system, lower respiratory system, chest wall and diaphragm. Upper respiratory system: The upper respiratory system comprises all structures and passages involved in the conduction of air from outside the body to the larynx. This system includes the nose, mouth and structures within the hypopharynx.
These 10 animal facts will amaze you. There are two fundamentally different types of laser eye surgery: PRK and LASIK. Under these two categories, there are several different flavors or modifications of each type. For example, LASEK (with an E) is a newer type of PRK.here are two fundamentally different types of laser eye surgery: PRK and LASIK. Under these two categories, there are several different flavors or modifications of each type.
Surgery for cataracts involves removing the natural lens of the eye that contains the cataract and either replacing it with an artificial lens called an intraocular lens implant (IOL) or compensating for its absence with eyeglasses or contact lenses. The most common replacement is an IOL.