The pharynx which is also known as the throat is a chamber shared by the digestive and respiratory systems. The pharynx extends from the base of the skull down to the inferior border of the cricoid cartilage (around the C6 vertebral level), where it becomes continuous with the esophagus. The food and air pathways cross each other in the pharynx. It has three subdivisions: the nasopharynx, the oropharynx, and the laryngopharynx. The nasopharynx is connecting to the nasal cavity by the internal nares and eustaintion tube. Common function as part of the respiratory system. The oropharynx is connecting to the month and the laryngoharynx is connecting to the esophagus. The chief action in which the muscles of the pharynx combine is deglutition (or swallowing), a complicated, neuromuscular act whereby food is transferred from (1) the mouth through (2) the pharynx and (3) the esophagus to the stomach.
The larynx which is also called voice box is the organ that connects the lower part of the pharynx with the trachea. It serves (1) as a valve to guard the air passages, especially during swallowing, (2) for the maintenance of a patent airway, and (3) for vocalization. It is external skeleton of cartilage plates that prevents collapse of the structure. The front set of plates is called thyroid cartilage, which is also known as “adams apple” these plates tend to be replacing by bone cells beginning of age 20 onward. Next is the epiglottis which is the upper part if the larynx when the