INTRODUCTION TO ANATOMY AND PHYSIOLOGY

Anatomy of the Ear

THE EAR AND ITS FUNCTION

 We often think of our ears as just performing the function of hearing!  However, they are also responsible to helping to maintain our balance.  When an ear infection occurs, or a blockage happens then not only do we experience pain but become aware that our balance is affected.

There are 3 main sections of the ear – they are:

  • The Outer Ear
  • The Middle Ear
  • The Inner Ear

How does the Ear work and what are the parts that form the process of hearing?

  • The Pinna is in the outer ear. This is the part that we see (the cartilage and soft tissue), and it is the antennae which collects soundwaves (in effect trapping them)
  • The auditory canal (middle ear) then receives these soundwaves (this is approximately 1” in length and diameter) then the soundwaves strike the eardrum (known as the tympanic membrane) as this vibrates, they are passed on to the ossicles (these are the three smallest bones in the body). The ossicles then pass them via amplified mechanical vibration and to the inner ear.
  • The cochlea (inner ear) in conjunction with the semi-circular canals (these are responsible for controlling our balance) the fluid in the cochlea contains sensory hearing cells which converts the mechanical vibrations into electrical impulses.
  • The auditory nerve then transmits the impulses to the brain, and we are able to understand what we have heard.

The Eustachian tube is an important part of the ear when it comes to carrying out this treatment.  The tube runs from the front wall of the middle ear down to the back of the nose and throat.  Its main function is to provide ventilation and access to the air outside, as well as to equalize the air pressure on both sides of the eardrum.  Children are more prone to ear infections, and a condition called glue ear, because their Eustachian tube is shorter and narrower than an adult. 

 

SINUS CAVITIES

In the facial part of the skull there are FOUR pairs of sinus cavities.   These can be subject to infection or becoming blocked.

Their function is to trap dust from the air, but they are also add resonance to our voice.

The sinuses produce mucous which cleanse the membranes of the nose and throat however when the cavities become congested or blocked the area can become extremely painful and an individual will experience tightness behind the eyes and ears.

The cavities are found below the eyes (maxillary), above the eyes (frontal), between the eyes (ethmoid) and further above the eyes (sphenoid).

Where are the cavities located?

  • Maxillary (below the eyes)
  • Frontal (above the eyes)
  • Ethmoid (between the eyes)
  • Sphenoid (above the eyes)

 

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