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Encyclopedia > Pinna
Pinna
The auricula. Lateral surface.
Latin auricula
Gray's subject #229 1034
Artery posterior auricular, anterior auricular
Nerve Trigeminal Nerve, Greater Auricular, Lesser Occipital
Lymph To Pre & Post Auricular Nodes, Nodes of Parotid and Cervical Chains
Dorlands/Elsevier a_73/12169627

The pinna (Latin for feather) is the visible part of the ear that resides outside of the head (this may also be referred to as the auricle or auricula). Image File history File links Gray904. ... Auricula can refer to: In botany, the plant Primula auricula, a type of primrose In anatomy, another name for the external portion of the ear, the pinna In anatomy, a small conical pouch that projects from each atrium of the heart. ... For other uses, see Latin (disambiguation). ... Section of an artery For other uses, see Artery (disambiguation). ... The posterior auricular artery is small and arises from the external carotid, above the Digastricus and Stylohyoideus, opposite the apex of the styloid process. ... The anterior auricular branches of the superficial temporal artery are distributed to the anterior portion of the auricula, the lobule, and part of the external meatus, anastomosing with the posterior auricular. ... Nerves (yellow) Nerves redirects here. ... In mammals including humans, the lymphatic vessels (or lymphatics) are a network of thin tubes that branch, like blood vessels, into tissues throughout the body. ... Elseviers logo. ... For other uses, see Latin (disambiguation). ... Two feathers Feathers are one of the epidermal growths that form the distinctive outer covering, or plumage, on birds. ... For other uses, see Ear (disambiguation). ...

Contents

Purpose

The purpose of the pinna is to collect sound. It does so by acting as a funnel, amplifying the sound and directing it to the ear canal. While reflecting from the pinna, sound also goes through a filtering process which adds directional information to the sound (see sound localization, head-related transfer function, pinna notch). The filtering effect of the human pinna preferentially selects sounds in the frequency range of human speech. The ear canal (external auditory meatus, external acoustic meatus), is a tube running from the outer ear to the middle ear. ... Sound localization is a listeners ability to identify the location of origin of a detected sound or the methods in acoustical engineering to simulate the placement of an auditory cue in a virtual 3D space (see binaural recording). ... HRTFs for left and right ear (expressed here as HRIRs) describe the filtering of a sound source (x(t)) before it is perceived at the left and right ears as xL(t) and xR(t), respectively. ... The pinna (Latin for feather) is the visible part of the ear that resides outside of the head (this may also be referred to as the auricle or auricula). ...


Amplification

Amplification of sound by the pinna, tympanic membrane and middle ear cause an increase in level of about 10 to 15 dB in a frequency range of 1.5 kHz to 7 kHz. This amplification is an important factor in inner ear trauma resulting from elevated sound levels. Inner ear The inner ear is the bony labyrinth, a system of passages comprising two main functional parts: the organ of hearing, or cochlea and the vestibular apparatus, the organ of balance that consists of three semicircular canals and the vestibule. ... In medicine, a trauma patient has suffered serious and life-threatening physical injury resulting in secondary complications such as shock, respiratory failure and death. ... Roadway noise is the main source of exposure Noise health effects, the collection of health consequences of elevated sound levels, constitute one of the most widespread public health threats in industrialized countries. ...


Pinna Notch

The pinna works differently for low and high frequency sounds. For low frequencies, it behaves similarly to a reflector dish, directing sounds toward the ear canal. For high frequencies, however, its value is more sophisticatedly reckoned. While some of the sounds that enter the ear travel directly to the canal, others reflect off the contours of the pinna first: these enter the ear canal at a very slight delay. Such a delay translates into phase cancellation, where the frequency component whose wave period is twice the delay period is virtually eliminated. Neighboring frequencies are dropped significantly. This is known as the pinna notch, where the pinna creates a notch filtering effect. Phase cancellation refers to the effect of two waves that are out of phase with each other being summed. ...


Anatomy

The diagram shows the shape and location of these components:

  • Anthelix (antihelix) forms a 'Y' shape where the upper parts are:
    • Superior crux (to the left of the fossa triangularis in the diagram)
    • Inferior crux (to the right of the fossa triangularis in the diagram)
  • Antitragus is below the tragus
  • Auricular sulcus is the depression behind the ear next to the head
  • Concha is the hollow next to the ear canal
  • Conchal angle is the angle that the back of the concha makes with the side of the head
  • Crus of the helix is just above the tragus
  • Cymba conchae is the narrowest end of the concha
  • External auditory meatus is the opening to the ear canal
  • Fossa triangularis is the depression in the fork of the anthelix
  • Helix is the folded over outside edge of the ear
  • Incisura anterior (auris) is between the tragus and the antitragus
  • Lobe (lobule) - attached or free according to a classic single-gene dominance relationship
  • Scapha
  • Tragus

A sulcus (pl. ... Anatomy of the human ear. ... The ear canal (external auditory meatus, external acoustic meatus), is a tube running from the outer ear to the middle ear. ... On the ear of humans and many other animals, the earlobe (lobulus auriculæ, sometimes simply lobe or lobule) is the soft lower part of the external ear or pinna. ... It has been suggested that dominant allele be merged into this article or section. ... In front of the concha, and projecting backward over the meatus, is a small pointed eminence, the tragus, so called from its being generally covered on its under surface with a tuft of hair, resembling a goat’s beard. ...

Embryology

The developing Pinna is first noticable around the sixth week of gestation in the human faetus, developing from six rounded protuberances (the six hillocks of Hiss) which are derived from the first and second branchial arches. These hillocks develop into the folds of the pinna and gradually shift upwards and backwards to their final position on the head. En-route accessory auricles (also known as preauricular tags - see below) may be left behind. The first three Hillocks are dervied from the 1st branchial arch and form the tragus, crus of the helix and helix respectively. Cutaneous sensation to these areas is via the trigeminal nerve, the attendent nerve of the 1st branchial arch. The final three Hillockes are derived from the 2nd branchial arch and form the antihelix, antitragus and lubule respectively. These portions of the ear are supplied by the cervical plexus and a small portion by the facial nerve. This explains why vesicles are classically seen on the Pinna in Herpes infection of the facial nerve ( Ramsay-Hunt Syndrome)


Abnormalities

There are various visible ear abnormalities:

  • Bat ear (also known as wingnut ear) — an ear that sticks out or protrudes
  • Cryptotia (hidden ear) — upper auricular sulcus not visible
  • Cup deformity — helical rim is compressed
  • Darwinian tubercle (auricular tubercle) — a projection from the helical rim
  • Lop ear — the top of the helical rim folded over
  • Macrotia (also known as big ears, or hypertrophy of the ears)
  • Microtia (small or partially developed ears0
  • Preauricular sinus (small holes usually visible from birth at the front of the ears where the pinna joins the head)
  • Accessory Auricles (small pieces of skin at the front of the ears where the pinna joins the head, vestigial remnants of the developing ears migration to it's final position)
  • Rim kinks — a kink of the helical rim
  • Stahl’s bar (also known as Spock ear) — third crus (in between the superior crux and inferior crux) making the top of the ear pointed
  • Zaheer's ear — having a deformed anti-tragus, which appears as a bump, as opposed to a protrusion, which would normally allow the snug insertion of earbud headphones

Unilateral Grade III microtia (left side). ... This article is about the Star Trek character. ... Headphones (also known as earphones, earbuds, stereophones, headsets, or by the slang term cans) are a pair of transducers that receive an electrical signal from a media player or receiver and use speakers placed in close proximity to the ears (hence the name earphone) to convert the signal into audible...

See also

An earring is a piece of jewelry that is worn on the ear. ... Body piercing is a form of body modification. ... Ear stapling is a form of body piercing that involves inserting a thin staple through a portion of the pinna—the visible part of the ear. ...

Additional images

External links


  Results from FactBites:
 
Pinna Abnormalities And Low-Set Ears - Health EncyclopediaNews Story - WNBC | New York (664 words)
Pinna abnormalities and low-set ears refer to?abnormalities in the shape or position of the outer ear (pinna or auricle).
During fetal development, the outer ear or "pinna" forms at a time when many other critical organs are developing (such as the kidneys).
Common abnormalities include abnormal folds in the pinna, prominence of the ears, low-set positioning, abnormal rotation of the pinna, and even absence of the pinna.
Pinna - Wikipedia, the free encyclopedia (377 words)
The pinna (Latin for feather) is the visible part of the ear that resides outside of the head.
We often use the pinna, which is also called the auricle, for hanging earrings and resting eyeglasses, pencils, and cigarettes; but the evolutionary purpose of the pinna is to collect sound.
While reflecting from the pinna, sound also goes through a filtering process which adds directional information to the sound (see sound localization, head-related transfer function, pinna notch).
  More results at FactBites »

 
 

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