Outer ear

Outer ear

External and middle ear, opened from the front. Right side.

The auricula. Lateral surface.
Latin auris externa
MeSH A09.246.272
TA A15.3.01.001
FMA 52781

Anatomical terminology

The outer ear is the external portion of the ear, which consists of the auricle (also pinna) and the ear canal. It gathers sound energy and focuses it on the eardrum (tympanic membrane).



Main article: Auricle (anatomy)

The visible part is called the auricle, also known as the pinna, especially in other animals. It is composed of a thin plate of yellow elastic cartilage, covered with integument, and connected to the surrounding parts by ligaments and muscles; and to the commencement of the ear canal by fibrous tissue. Many mammals can move the pinna (with the auriculares muscles) in order to focus their hearing in a certain direction in much the same way that they can turn their eyes. Most humans do not have this ability. [1]

Ear canal

Main article: Ear canal

From the pinna the sound waves move into the ear canal (also known as the external acoustic meatus) a simple tube running through to the middle ear. This tube leads inward from the bottom of the auricula and conducts the vibrations to the tympanic cavity and amplifies frequencies in the range 3 kHz to 12 kHz.


Intrinsic muscles

Intrinsic muscles of external ear

The muscles of the auricula
Nerve Facial nerve
Actions Undeveloped in humans
TA A15.3.01.001
FMA 52781

Anatomical terms of muscle

The intrinsic muscles of the external ear are the:

Extrinsic muscles

Auricular muscles

The muscles of the pinna

Auricular muscles in context with the other facial muscles
Origin Galeal aponeurosis
Insertion Front of the helix, cranial surface of the pinna
Artery Posterior auricular artery
Nerve Facial nerve
Actions Undeveloped in humans (wiggle ears)
Latin Musculi auriculares
TA A15.3.01.001
FMA 52781

Anatomical terms of muscle

The auricular muscles (or extrinsic muscles) are the three muscles surrounding the auricula or outer ear:

The superior muscles is the largest of the three, followed by the posterior and the anterior.

In some mammals these muscles can adjust the direction of the pinna. In humans these muscles possess very little action. The auricularis anterior draws the auricula forward and upward; the Auricularis superior slightly raises it; and the Auricularis posterior draws it backward.


One consequence of the configuration of the outer ear is selectively to boost the sound pressure 30- to 100-fold for frequencies around 3 kHz. This amplification makes humans most sensitive to frequencies in this range — and also explains why they are particularly prone to acoustical injury and hearing loss near this frequency. Most human speech sounds are also distributed in the bandwidth around 3 kHz.[2]

Clinical significance

Malformations of the external ear can be a consequence of hereditary disease, or exposure to environmental factors such as radiation, infection. Such defects include:


Usually, malformations are treated with surgery, although artificial prostheses are also sometimes used.[4]

If malformations are accompanied by hearing loss amenable to correction, then the early use of hearing aids may prevent complete hearing loss.[3]


This article incorporates text in the public domain from the 20th edition of Gray's Anatomy (1918)

  1. http://www.livescience.com/33809-wiggle-ears.html
  2. Purves, Dale, George J. Augustine, David Fitzpatrick, William C. Hall, Anthony-Samuel LaMantia, James O. McNamara, and Leonard E. White (2008). "Chapter 13". Neuroscience. 4th ed. Sinauer Associates. p. 317. ISBN 978-0-87893-697-7.
  3. 1 2 3 4 5 6 7 Богомильский, Чистякова 2002.
  4. 1 2 3 Пальчун, Крюков 2001.
  5. 1 2 СЭС 1986.
  6. 1 2 Асанов и др. 2003.
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