Anatomy, Blood Supply, and Innervation of the External Ear

The external ear is a crucial structure involved in hearing and protection. It consists of the auricle (pinna) and external auditory canal.

Anatomy of the External Ear

Auricle (Pinna)

The auricle is composed of elastic cartilage covered by skin and serves to collect sound waves.

• Helix: Outer curved ridge.
• Antihelix: Inner curved ridge.
• Tragus: Small projection near the ear canal opening.
• Lobule: The soft lower portion.

External Auditory Canal

A tube-like structure leading to the tympanic membrane, lined with hair and ceruminous glands that protect against pathogens.

Blood Supply of the External Ear

Arterial supply is derived mainly from the external carotid artery.

• Posterior Auricular Artery: Supplies the auricle and surrounding tissue.
• Superficial Temporal Artery: Provides blood to the upper auricle.
• Deep Auricular Artery: Supplies the external auditory canal.

Innervation of the External Ear

The external ear receives sensory innervation from multiple cranial and cervical nerves.

• Great Auricular Nerve (C2, C3): Innervates the lower part of the auricle.
• Auriculotemporal Nerve (CN V3): Provides sensation to the anterior auricle.
• Facial Nerve (CN VII): Contributes minor sensory fibers.
• Vagus Nerve (CN X): Innervates parts of the external auditory canal.