The Pharynx

The Pharynx

• Funnel-shaped tube about 13 cm long
• Starts at the internal nares and extends to the level of the cricoid cartilage
• Lies posterior to the nasal and oral cavities
• Superior to the larynx
• just anterior to the cervical vertebrae
• wall composed of skeletal muscles that assists in deglutition
• lined with mucous membrane

Functions of the Pharynx

 Passageway for air and water
 Provides a resonating chamber for speech sounds
 Houses the tonsils, which participate in immunological reactions against foreign invaders

Anatomical Regions of the pharynx:

1. Nasopharynx –the superior portion of the pharynx. It lies posterior to the nasal cavity and extends to the soft palate.

 Receives air and packages of dust-laden mucus from the nasal cavity through the internal nares.
 Lined with pseudostratified columnar epithelium; the cilia move the mucus toward the most inferior part of the pharynx.
 Also exchanges small amounts of air with the auditory tubes to equalize pressure between the pharynx and the middle ear.

*soft palate – an arch shaped muscular partition between the nasopharynx and oropharynx. It forms the posterior portion of the roof of the mouth and is lined by a mucous membrane.

5 openings in the wall of the soft palate:
 2 internal nares
 2 openings leading to the auditory/pharyngotymphanic tubes (Eustachian tubes)
 Pharyngeal tonsil (adenoid) – found on the posterior wall

2. Oropharynx - the intermediate portion of the pharynx. It lies posterior to the oral cavity and extends from the soft palate inferiorly to the level of the hyoid bone.

 Has only 1 opening, the fauces, which is an opening from the mouth.
 Has both respiratory and digestive functions. It serves as a common passageway for air, food and drink.
 Subject to abrasion by food particles
 Lined with nonkeratinized stratified squamous epithelium
 Location of 2 tonsils (palatine and lingual)

3. Laryngopharynx/Hypopharynx – the inferior portion of the pharynx

• Begins at the level of the hyoid bone
• Inferior end opens into the esophagus posteriorly and the larynx anteriorly
• Both a respiratory and digestive pathway
• Lined by nonkeratinized stratified squamous epithelium


Source: Principles of Anatomy and Physiology 12th edition
By: Gerard J. Tortora and Bryan H. Derrickson