Pharynx

Pharynx or Throat

Pharynx is 12-14cm long funnel shape tube - extends from base of skull to level of 6th cervical vertebrae.

Pharynx is connected to nasal cavity through internal nares, also connected mouth or oral cavity.

Organ Associated with Pharynx

Superiorly - inferior surface of base of skull

Inferiorly - esophagus trachea

Anterior - nose, mouth, Larynx

Posteriorly - first 6 cervical vertebrae

Divisions of Pharynx

Pharynx divided into three section-

1. Nasopharynx - above the soft palate

2. Oropharynx - lie between soft palate and hyoid bone

3. Laryngopharynx (hypopharynx) - lie between hyoid bone and larynx

1. Nasopharynx

Superior portion of pharynx to the soft palate.

Lies behind the nose.

Opening in Nasopharynx

There are five opening in nasopharynx-

1. 2 Internal nares

2. 2 Opening into auditory tubes

3. Opening into oropharynx

(Posterior wall of pharynx contain pharyngeal tonsil, also known as adenoid or nasopharyngeal tonsil)

Nasopharynx recieves air from nasal cavity through internal nares (with mucus).

             

Nasopharynx lined with pseudo stratified epithelium and cilia move the mucus down toward anterior part of pharynx.

2. Oropharynx

Oropharynx have one opening; opening from the mouth into pharynx is oropharynx.

Oropharynx lies posteriorly to oral cavity and extend from soft palate inferiorly to the level of hyoid bone.

Oropharynx lined with nonkeratinized stratified squamous epithelium.

Passage for food moving from the mouth to the esophagus and air moving to and from nasal cavity.

3. Laryngopharynx (Hypopharynx)

Laryngopharynx is both respiratory and digestion pathway.

It extends from upper border of epiglottis to lower border of cricoid catilage. Lower border of cricoid cartilage refer the junction between larynx and trachea.

Lined with moist non- keratinized stratified squamous epithelium.

At point pharynx is divided anteriorly into the larynx and posteriorly into the esophagus.

Layers of Pharynx

Function of Pharynx