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
