Eustachian Tube – Structure And Functions

Eustachian Tube – Structure And Functions

Briefly describe the pharyngotympanic tube/auditory tube/eustachian tube.
Answer.

Pharyngotympanic Tube General description

• It is a funnel-shaped osseocartilaginous tube that connects the middle ear cavity (tympanum) with the nasopharynx.
• It is about 4 cm (36 mm) long.
• It is directed downwards, forward, and medially.
• Its bony part forms the lateral one-third of the tube, while its cartilaginous part forms the medial two-third of the tube.
• Its bony part (12 mm long) lies at the base of the skull, lateral to the carotid canal below the tympanic plate of the temporal bone.
• Its cartilaginous part (24 mm long) lies in sulcus tubae – a groove between the greater wing of the sphenoid and the apex of the petrous temporal bone.

Pharyngotympanic Tube Function Maintains equilibrium of air pressure on either side of the tympanic membrane for its proper vibration by the sound waves.

Pharyngotympanic Tube Applied anatomy This provides passage for infection to travel from the upper respiratory tract (URT) to middle ear causing otitis media. The otitis media is common in children because the auditory tube is much shorter (18 mm) and straight in them.