How does pharynx help in respiratory work?

Pharynx is a muscular passage extending from nasal cavity to larynx. It is composed of 3 parts- nasopharynx, oropharynx and laryngopharynx. The inhaled air travels from nasal cavity to oropharynx via nasopharynx. From oropharynx air enters into larynx through laryngopharynx. The epiglottis acts as a lid due to which air enters the trachea and not into the alimentary canal. The trachea thus provides a clear airway for air to enter the lungs and also leave the lungs.