Auricle

Auricle

The auricle, also known as the pinna, is the visible part of the outer ear that resides outside the head. It plays a crucial role in the sense of hearing by collecting and directing sound waves into the ear canal towards the eardrum.

Anatomy

The auricle is composed of a thin plate of elastic cartilage covered by skin. It has several distinct parts:

• The helix is the outer rim of the auricle.
• The antihelix is a curved prominence of cartilage parallel to the helix.
• The concha is the deep cavity in front of the ear canal.
• The tragus is a small pointed eminence of the external ear.
• The antitragus is a small tubercle opposite the tragus.
• The lobule (earlobe) is the fleshy lower part of the auricle.

Function

The primary function of the auricle is to capture sound waves and funnel them into the ear canal. Its shape helps to amplify and direct sounds from the environment into the middle ear and inner ear, where they are processed and interpreted by the brain.

Development

The auricle develops from six small swellings called the hillocks of His, which form around the first and second pharyngeal arches during embryonic development. These hillocks gradually fuse and reshape to form the mature auricle.

Clinical Significance

The auricle can be affected by various medical conditions, including:

• Auricular hematoma: A collection of blood within the cartilage of the ear.
• Microtia: A congenital deformity where the auricle is underdeveloped.
• Otoplasty: A surgical procedure to correct deformities or improve the appearance of the auricle.

Related Pages

• Outer ear
• Middle ear
• Inner ear
• Hearing
• Elastic cartilage
• Ear canal
• Eardrum
• Brain
• Pharyngeal arches
• Auricular hematoma
• Microtia
• Otoplasty