The pharynx or throat region is the open upper end of the digestive and respiratory tubes and is a musculomembranous tube that serves as a common route for food and air. The pharynx is critical to such important activities as chewing, swallowing, breathing and speaking. This area is really a cylindrical space lined with thin muscles on the superior, posterior and lateral surfaces. It is bounded anteriorly by the posterior nasal and oral cavities, posteriorly by the vertebral column, superiorly by the base of the skull and inferiorly by the cricoid cartilage of the larynx (the level of the sixth cervical vertebra).

The pharynx can be divided into three separate regions.

• The nasal pharynx (nasopharynx) between the base of the skull and the soft palate.
• The oral pharynx (oropharynx) between the soft palate and epiglottis.
• The laryngeal pharynx (laryngopharynx) between the epiglottis and cricoid cartilage of the larynx.

Figure 8-3
Midsagittal aspect of the head and neck.

The pharynx is best visualized by looking at a mid-sagittal section of the head. Note how the cylinder is open at the top, front and bottom. Note also how the pathways for food and air cross each other. This latter fact is critical in understanding the complexities of swallowing. (Figure 8-3)