Successfully reported this slideshow.
We use your LinkedIn profile and activity data to personalize ads and to show you more relevant ads. You can change your ad preferences anytime.

Becoming familiar with the outer ear

296 views

Published on

  • Be the first to comment

  • Be the first to like this

Becoming familiar with the outer ear

  1. 1. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  The human auditory system can beThe human auditory system can be divided into two sub-systems.divided into two sub-systems. They are:They are: 1.1. The peripheral auditory systemThe peripheral auditory system 2.2. The central auditory systemThe central auditory system
  2. 2. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  The peripheral auditory system isThe peripheral auditory system is further divided into three segments:further divided into three segments: 1.1. The outer earThe outer ear 2.2. The middle earThe middle ear 3.3. The inner earThe inner ear
  3. 3. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  The central auditory system consists ofThe central auditory system consists of thethe neural pathwaysneural pathways from thefrom the cochlearcochlear nucleusnucleus to theto the auditory cortexauditory cortex located inlocated in the temporal lobe of the brain.the temporal lobe of the brain. Note:Note: We will have further discussion of theWe will have further discussion of the central auditory system in the future.central auditory system in the future.
  4. 4. Becoming familiar with the OuterBecoming familiar with the Outer EarEar The development of the outer ear beginsThe development of the outer ear begins before the second fetal month. Thebefore the second fetal month. The annulus for the tympanic membrane isannulus for the tympanic membrane is formed in the third fetal month.formed in the third fetal month.
  5. 5. Becoming familiar with the OuterBecoming familiar with the Outer EarEar The Auricle or Pinna is the soft tissueThe Auricle or Pinna is the soft tissue forming a cup to the entrance of theforming a cup to the entrance of the external auditory meatus (ear canal)external auditory meatus (ear canal)
  6. 6. Becoming familiar with the OuterBecoming familiar with the Outer EarEar It is very important to learn theIt is very important to learn the “landmarks” of the auricle/pinna“landmarks” of the auricle/pinna (ref. Lass & Woodford page 51).(ref. Lass & Woodford page 51). Many of these “landmarks” will beMany of these “landmarks” will be routinely used in your daily clinicroutinely used in your daily clinic practice.practice.
  7. 7. Becoming familiar with the OuterBecoming familiar with the Outer EarEar
  8. 8. Becoming familiar with the OuterBecoming familiar with the Outer EarEar
  9. 9. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  The adult external auditory meatusThe adult external auditory meatus is about an one and one-halfis about an one and one-half inches long and generally and Sinches long and generally and S shape.shape.
  10. 10. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  Between the sound collection of theBetween the sound collection of the Pinna and the shape of the ear canal,Pinna and the shape of the ear canal, there is a natural peak acousticthere is a natural peak acoustic resonance of about 15 decibels atresonance of about 15 decibels at 2700Hz.2700Hz. Note: This resonance is variable from ear to ear.Note: This resonance is variable from ear to ear.
  11. 11. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  The ear canal can be described in twoThe ear canal can be described in two distinct portions. They are:distinct portions. They are: 1.1. The cartilaginous portion (closest to theThe cartilaginous portion (closest to the opening of the ear canal).opening of the ear canal). 2.2. The bony portion (closest to theThe bony portion (closest to the typmanic membrane/eardrum).typmanic membrane/eardrum).
  12. 12. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  In the cartilaginous portion, you haveIn the cartilaginous portion, you have two sets of glands and also hairtwo sets of glands and also hair folliclesfollicles..
  13. 13. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  The sebaceous glands produce oil.The sebaceous glands produce oil.  The ceruminous glands produce wax.The ceruminous glands produce wax.  The hair, oil, and wax all serve to protectThe hair, oil, and wax all serve to protect the ear canal and eardrum from foreignthe ear canal and eardrum from foreign materials.materials.
  14. 14. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  Otoscopic viewing of the adult ear canalOtoscopic viewing of the adult ear canal requiresrequires pulling up and backpulling up and back on the pinnaon the pinna to straighten the ear canal forto straighten the ear canal for observation of both it and the eardrum.observation of both it and the eardrum.
  15. 15. Becoming familiar with the OuterBecoming familiar with the Outer EarEar  The view of the eardrum is broken intoThe view of the eardrum is broken into four quadrants. It is important tofour quadrants. It is important to remember these four quadrants as youremember these four quadrants as you will use them often in writingwill use them often in writing patient/client reports.patient/client reports.
  16. 16. Becoming familiar with the OuterBecoming familiar with the Outer EarEar The four quadrants are:The four quadrants are: 1.1. Anterior inferiorAnterior inferior (where you find the cone of light)(where you find the cone of light) 2.2. Anterior superiorAnterior superior 3.3. Posterior superiorPosterior superior 4.4. Posterior inferiorPosterior inferior (ref. Lass & Woodford page #54)(ref. Lass & Woodford page #54)
  17. 17. Becoming familiar with the OuterBecoming familiar with the Outer EarEar
  18. 18. Becoming familiar with the OuterBecoming familiar with the Outer EarEar

×