External ear

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~~We have no content here yet, it's a place-holder for~~The external ear comprises the ~~images only. Please improve radiopaedia~~auricle (or pinna), the external auditory meatus, and ~~add content - it~~the tympanum (eardrum). The pinna concentrates and amplifies sound waves and funnels them through the outer acoustic pore into the external auditory meatus, which carries them to the tympanic membrane.

Gross anatomy

Auricle (pinna)

The auricle is the part of the ear that projects laterally from the head. It is composed of an irregular concave plate of elastic cartilage and dense connective tissue, covered by skin which contains short hairs (tragi), sebaceous glands, and ceruminous glands.

Structure

The auricle has a complex shape that is composed of several ridges, notches, and grooves:

helix: posterior free margin of the auricle
anthelix: a ridge parallel to the helix
- crura anthelicis: a pair of limbs located above the external acoustic pore
- fossa triangularis:tiny depression between thecrura
scaphoid fossa: the depression between the helix and anthelix
tragus: prominence in front of the external acoustic pore
- can be manually pushed back over the pore, to mitigate noise
antitragus: situated in the lower part of the anthelix and faces the tragus
intertragic incisure: a notch separating the tragus from the antitragus
cavum conchae: the deepest depression in the auricle, inferior to the crus of the helix
cymba conchae: depression surrounded by the crus of the helix
ear lobe: the lowest part of the ear and the only ~~takes~~part that does not contain cartilage, situated below the intertragic incisure

Vascular supply

The auricle is supplied by

the posterior auricular branch of the external carotid artery
the superficial temporal artery
a branch from the occipital artery

Innervation

facial nerve: innervates the external auricular muscles

External auditory meatus

The external auditory meatus is a ~~few minutes~~short canal leading from the auricle to the tympanic membrane. It is lined by skin containing hair follicles (tragi), sebaceous glands, and ceruminous glands.

Tympanum

The tympanic membrane consists of two layers of collagen fibres:

an outer layer with a radial fibre arrangement
an inner layer with a circular fibre arrangement

It has an outer cover of extremely thin skin and an inner layer of cuboidal epithelium facing the tympanic cavity.

~~-<p><em style="line-height: 1.5;">We have no content here yet, it's a place-holder for the images only. Please improve radiopaedia and add content - it only takes a few minutes. </em></p>~~
+<p>The <strong>external ear</strong> comprises the auricle (or pinna), the <a href="/articles/external-auditory-canal">external auditory meatus</a>, and the <a href="/articles/tympanic-membrane">tympanum</a> (eardrum). The pinna concentrates and amplifies sound waves and funnels them through the outer acoustic pore into the external auditory meatus, which carries them to the tympanic membrane.</p><h4>Gross anatomy</h4><h5>Auricle (pinna)</h5><p>The auricle is the part of the ear that projects laterally from the head. It is composed of an irregular concave plate of elastic cartilage and dense connective tissue, covered by skin which contains short hairs (tragi), sebaceous glands, and ceruminous glands.</p><h6>Structure</h6><p>The auricle has a complex shape that is composed of several ridges, notches, and grooves:</p><ul>
+<li>
+<strong>helix</strong>: posterior free margin of the auricle</li>
+<li>
+<strong>anthelix</strong>: a ridge parallel to the helix<ul>
+<li>
+<strong>crura anthelicis</strong>: a pair of limbs located above the external acoustic pore</li>
+<li>
+<strong>fossa triangularis</strong>:<strong> </strong>tiny depression between the<strong> </strong>crura</li>
+</ul>
+</li>
+<li>
+<strong>scaphoid fossa</strong>: the depression between the helix and anthelix </li>
+<li>
+<strong>tragus</strong>: prominence in front of the external acoustic pore<ul><li>can be manually pushed back over the pore, to mitigate noise</li></ul>
+</li>
+<li>
+<strong>antitragus</strong>: situated in the lower part of the anthelix and faces the tragus</li>
+<li>
+<strong>intertragic incisure</strong>: a notch separating the tragus from the antitragus</li>
+<li>
+<strong>cavum conchae</strong>: the deepest depression in the auricle, inferior to the crus of the helix</li>
+<li>
+<strong>cymba conchae</strong>: depression surrounded by the crus of the helix</li>
+<li>
+<strong>ear lobe</strong>: the lowest part of the ear and the only part that does not contain cartilage, situated below the intertragic incisure</li>
+</ul><h6>Vascular supply</h6><p>The auricle is supplied by</p><ul>
+<li>the posterior auricular branch of the external carotid artery</li>
+<li>the superficial temporal artery</li>
+<li>a branch from the occipital artery</li>
+</ul><h6>Innervation</h6><ul>
+<li>facial nerve: innervates the external auricular muscles</li>
+<li> </li>
+</ul><h5>External auditory meatus</h5><p>The external auditory meatus is a short canal leading from the auricle to the tympanic membrane. It is lined by skin containing hair follicles (tragi), sebaceous glands, and ceruminous glands.</p><h5>Tympanum</h5><p>The tympanic membrane consists of two layers of collagen fibres:</p><ul>
+<li>an outer layer with a radial fibre arrangement</li>
+<li>an inner layer with a circular fibre arrangement</li>
+</ul><p>It has an outer cover of extremely thin skin and an inner layer of cuboidal epithelium facing the <a href="/articles/middle-ear">tympanic cavity</a>.</p>

References changed:

1. András Csillag. Atlas of the Sensory Organs. (2007) ISBN: 9781592598496 - <a href="http://books.google.com/books?vid=ISBN9781592598496">Google Books</a>
2. Susan Standring. Gray's Anatomy. (2008) ISBN: 9780443066849 - <a href="http://books.google.com/books?vid=ISBN9780443066849">Google Books</a>
2. Susan Standring. Gray's Anatomy. (2008) ISBN: 9780443066849 - <a href="http://books.google.com/books?vid=ISBN9780443066849">Google Books</a>
2.

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