Anatomy of the Middle Ear Tympanic Cavity

Middle Ear Anatomy

• The tympanic membrane makes an angle of 45 degrees with the floor of the external auditory meatus.

Blood Supply

• The tympanic branch of the middle meningeal artery enters the middle ear cavity through the petrotympanic fissure.

Venous Drainage

• The superior petrosal sinus drains the veins of the middle ear.

Pressure Regulation

• The Eustachian tube equalizes pressure on either side of the tympanic membrane.

Nerve Supply

• The tympanic branch of the glossopharyngeal nerve (CN IX) supplies the middle ear.

Tympanic Cavity Boundaries

• The tegmen tympani separates the tympanic cavity from the middle cranial fossa.
• The lateral wall of the tympanic cavity is formed by the squamous part of the temporal bone.

Tympanic Cavity Structures

• The tendon of the tensor tympani muscle emerges from the apex of the pyramid in the tympanic cavity.

Posterior Wall Structures

• The antrum of the mastoid process is located below the aditus to the mastoid antrum in the posterior wall of the tympanic cavity.

Bony Floor Variations

• The bony floor separating the tympanic cavity from the superior bulb of the internal jugular vein may be replaced by a thin plate of bone or a fibrous Bridge.

Explore the anatomy of the middle ear tympanic cavity, located inside the petrous part of the temporal bone. Learn about its boundaries, including the roof, floor, and walls, as well as its structures like the epitympanic recess and mucous membrane lining.