Anatomy of the Ear: Temporal Bone and Auricle

Temporal Bone

• Consists of three parts: squamous, petrous and tympanic.
• Squamous part is superior and forms the lateral wall of the skull.
• Petrous part is inferior and contains the bony labyrinth of the inner ear.
• Tympanic part communicates with the tympanic cavity and contains the mastoid cells.

Auricle

• Visible part of the ear.
• Located on each side of the head between the mastoid process and the temporal bone.
• Size varies between individuals and is typically 6-8 cm in height and 3-5 cm in width.
• Made of cartilage covered with skin for flexibility and sound optimization.

External Auditory Canal (EAC)

• Extends from the auricle to the eardrum.
• Acts as a resonator.
• Approximately 2.5-3 cm long and narrows in the middle.
• Conducts sound waves to the tympanic membrane.
• Produces earwax to protect the inner ear.
• Located in the temporal bone and ends at the tympanic membrane.
• Initial part is cartilaginous and has an S-shaped form.

EAC Walls

• Anterior: Parotid gland and the temporomandibular joint.
• Posterior: Bone separating the EAC from the mastoid air cells.
• Inferior: Parotid gland.
• Superior: Middle cranial fossa.
• External: External acoustic meatus.
• Internal: Tympanic membrane.

Blood Supply

• The EAC is supplied by the external carotid artery.

Nerves

• Auriculotemporal nerve: Supplies the helix and tragus.
• Facial nerve: Supplies the auricle, concha, and part of the antihelix.
• Cervical plexus: Supplies the lobule, helix, and antitragus.
• Vagus, facial, and trigeminal nerves: Innervate the external auditory canal.

Functions

• Auricle: Collects sounds.
• External Auditory Canal: Conducts sounds and amplifies certain frequencies.

This quiz explores the anatomy of the ear, focusing on the temporal bone, auricle, and external auditory canal. It covers their structure, function, and significance in hearing. Test your knowledge of ear anatomy with detailed questions on these components.