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.
The LASIK surgery is performed by an ophthalmologist who uses a laser or microkeratome to reshape the eye's cornea in order to improve visual acuity. For most patients, LASIK provides a permanent alternative to eyeglasses or contact lenses. LASIK is most similar to another surgical corrective procedure, photorefractive keratectomy (PRK), and both represent advances over radial keratotomy in the surgical treatment of refractive errors of vision.