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.
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.
Cataract surgery is usually performed under local anaesthetic. Your surgeon will make a tiny incision (cut) in your cornea (the outer layer of your eye). Using a tiny probe that emits ultrasound waves, the surgeon will break up the cataract and remove the pieces from your eye. This is called phacoemulsification.