Anatomy of the Ear

The ear is composed of three parts, the Outer visible part, the middle and the inner ear.  The outer and middle ears primary function is to collect sound and vibrate it.  The inner ear then transmutes this into sound by using impulses that are sent to the brain.

The Outer Ear is made up of the pinna cartilage and the softer fleshy lobe, it forms a spiral shape which helps to collect sound and guide it into the Middle Ear canal (Meautus). In the middle ear tiny hairs and wax cells (cerumen) help to catch debris, dust and foreign bodies.  On average 2.5cm long in adults the middle ear ends at the tympanic membrane or ear drum.  The Tympanic Membrane (Ear Drum) is exactly like the surface of a drum, taught skin is designed to vibrate in response to sound waves, frequencies and changes in air pressure that make up sounds.  It is a thin membrane and is the point at which the outer ear becomes the middle ear.  Ear candles do not go deep enough to damage the ear drum, only acute changes in pressure or trauma can cause damage.

The Middle Ear is a small area between the outer and inner ear that contains the bones.  The tiny bones are called ossicles and conduct sound between the ear drum and the inner ear producing a more defined vibration.  They are each defined by their shape.

The Malleus (Hammer) is attached to the eardrum

The Incus (Anvil) is stretched between the malleus and the stapes

The Stapes (Stirrup) is attached to the oval window of the inner ear

Together these bones create a link for vibration between the tympanic membrane and the inner ear.  The middle ear is linked to the Eustachian tube which goes to the back of the nose (this can mean that build ups in the nose or ear can be easily transferrable).   The eustation tube is opened by muscle contraction when swallowing or yawning, which is why it can sometimes relieve a blockage after a change of air pressure.  It acts as a ventilation tube.

The Inner Ear is very delicate and controls balance and conversion of good sound vibrations, and conducting these to the brain for interpretation.    The semi circular canals are the means of balance being set at the right angles to each other.  They are attached to the Utricle and Saccule and contain hairs bathed in fluid which sway with movement.  When fluid lags behind nerve impulses convey which direction you are moving in to the brain, this can sometimes be a delayed response which can cause us to fell off balance or dizzy.  One controls horizontal movement (spinning/turning) and the other movements like jumping or falling, and even slight movements of the head.

The mechanism of hearings in the cochlear which looks similar to a snail shell.  This receives the final vibrations that have come via the pinna, the malleus, the tympanic membrane, the bones of the middle ear and the vibration against the oval window.  The Cochlear transmits the vibrations along the auditory or cochlea nerve to the brain to be interpreted as sound and the vestibular nerve transmits information on balance.

What about Ear Wax?

Ear wax is a secretion of Yellow or brown colour and is produced by two glands in the outer ear canal.  It is acidic and designed to repel fungi and bacteria and any unwanted debris.  Secretions can be stimulated by irritation, excess water, blockages and extra debris.  The sticky part of the cerumen should stop dust and debris entering the ear.  If irritation continues, a build up can cause deafness.  Usually the secretions move themselves as we move our jaw, but irritation, cotton buds and other objects put in the ear can cause excess wax.  Excess wax or very dry wax can be a sign of certain conditions and should be referred to a gp to be resolved. 

Treatments to remove a build up of wax…

Ear syringing – Carried out by medical staff or doctors.  There is a slight risk of perforation of the ear drum.

Ear wax softening agents – Occasionally they can irritate and cause otitis externia (Outer ear infection). 

Sharp object in the ear – People often use cotton buds, pencils, wire, hair grips etc themselves to remove ear wax, but this risks outer and inner ear infections.

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