PHARYNX

PHARYNX

1.       INTRODUCTION :  it is a common passage for both air & food. It is a muscular tube lined by mucus membrane.

2.       SITUATION : situated at the base of the skull to the level of sixth cervical vertebra.

3.       MEASUREMENT :  about  12 cm

4.       STRUCTURE :

The pharynx is divided into three parts:

1.       Nasopharynx

2.       Oropharynx

3.       Laryngopharynx

NASOPHARYNX :

Ø  It lies behind the nose above the level of soft palate.

Ø  The lateral wall contains opening of pharygotympanic tube (auditory tube), which leads to the middle ear.

Ø  On the posterior wall is the pharyngeal tonsil.

Ø  It is well developed in children  & small or absent in adults.

Ø  An enlarged pharyngeal tonsil is called adenoids.

      OROPHARYNX :

Ø  It lies behind the mouth below the level of soft palate.

Ø  It contains the palatine tonsils on its lateral wall.

     LARYNGOPHARYNX :

Ø  It extends from the  oropharynx  & continue as esophagus below.

     MUSCLES OF PHARYNX :

The wall of pharynx is formed by mainly three pairs of constrictive muscles.

·         Superior constrictor

·         Middle constrictor

·         Inferior constrictor

5.       BLOOD SUPPLY :

ARTERIAL SUPPLY : branches of external carotid , facial & maxillary arteries.

VENOUS DRAINAGE : internal jugular and facial vein .

6.       NERVE SUPPLY :

Pharynx  is supplied by pharyngeal plexus of nerves formed by branch of vagus,  branch of glossopharyngeal nerve & branches of superior cervical sympathetic ganglion.

7.       APPLIED ANATOMY :

Ø  Pharyngitis – inflammation of pharynx

Ø  Tonsillitis : inflammation of tonsils.

8.       FUNCTIONS :

v  It act as passage for both air and food.

v  It play and important role in hearing.

v  The palatine tonsil & pharyngeal tonsil protects the body from microorganism.