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The Ear
Functions of the ear
Hearing – detects vibrations in air and converts these vibrations to nerve impulses
Impulses are sent to the brain and interpreted as sounds
Balance – vestibule in inner ear is responsible for balance
It detects changes in body position and sends this info to brain via nerve impulses
Anatomy & Physiology of Ear
There are three divisions of the ear
1. External ear – the pinna ( or auricle) gathers and passes sound vibrations through the auditory canal
2. Middle ear – the tympanum (or eardrum) transmits sound vibrations to in inner ear
3. Inner ear – also known as labrinyth receives sound vibrations and transmits messages to brain via nerve impulses
Middle Ear Ossicles
There are three bones called ossicles
Malleus – (hammer) Incus Stapes – (stirrup)
The ossicles transmit vibrations from the
tympanic membrane to the inner ear
Inner Ear - Cochlea
Cochlea is known as the organ of hearing Cochlea is a snail shaped structure filled with
fluid and hair cells These cells respond to vibrations in the fluid
and produces nerve impulses The impulses are sent to the auditory centre
of the brain
Word componentsWord root Combining
formMeaning
Acoust acoust/o hear/sound
Audi audi/o hear/hearing
Aur aur/o,aural ear
Auricul auricul/o ear / pinna
Cerumin cerumin/o cerumen / ear wax /
Cochle cochle/o cochlea,snail (receptor for hearing in inner ear
Incud incud/o,incudal incus bone or anvil
Word ComponentsWord root
Combining form
Meaning
Labrinyth labrinyth/o maze, twisted spiral shape
Malle Malle/o Malleus bone or hammer
Mast Mastoid/o breast, nipple shaped
Myring myring/o membrane
Ot ot/o ear
Staped stapedi/o
staped/o
stapes bone or stirrup
Salping salping/o eustachian or trumpet tube
Tympan tympan/o drum pg 1
Ear inflammation / infections
Otitis externa
Otitis media
Otitis interna
Otitis media - more common due to the middle ear’s connection to Eustachian tube
pg2
Procedures for ear
Examination – aural speculum allows better viewing of tympanic membrane with auriscope
Auriscope – instrument used to examine ear canal and tympanic membrane
Aural syringe – instrument used to lavage (wash out) ear that is blocked with cerumen
pg2
Glue ear Is the build up of fluid behind tympanic
membrane Surgical puncture…..allows drainage from
middle ear Fluid drains into Eustachian tube to
nasopharynx Grommets can be fixed to tympanic
membrane to assist drainage pg3
AbbreviationsAC air conduction
AD auris dextra(right ear)
AS auris sinistra (left ear)
Aud audiology
BC bone conduction
ENT ear, nose throat
ETF eustachian tube function
OE otitis externa
OM otitis media
Oto otology
Ear Conditions / Terms
Term Meaning
conductive deafness
hearing impairment resulting from obstruction of sound waves
glue ear accumulation of fluid in middle ear
Menieres Disease
disorder of inner ear characterized by vertigo, deafness and tinnitus
otalgia pain in ear (earache)
otorrhagia bleeding from the ear
tinnitus continuous ringing or buzzing noise in ear
Vertigo dizziness, sensation the the person or surroundings are spinning
Ear procedures
Procedure Meaning
audiogram recording tracing of hearing
myringoplasty surgical repair of perforated ear drum
myringotomy surgical incision into the eardrum
ossiculoplasty surgical repair of the ear bones
otoplasty plastic surgery of the ear
stapedectomy removal of the stapes
tympanoplasty surgical repair of the tympanic membrane when disease such as infection involved
THE EYE
Organ of sight
Function of the eye
Identification of shapes and colours
Physiology of vision
Light enters eye through the pupil The lens focuses light rays on the retina
which is the nerve tissue of the eye Visual receptor neurons (known as rods and
cones) in retina respond to these light rays Nerve fibres join in the optic disc Optic disc carries nerve impulses to the brain
Professional branches of vision
Optometry Is the measuring of visual acuity and fitting of
glasses to correct visual defects
Ophthamology Is the study of the eye and vision
Opticianry Is the practice of filling prescriptions for glasses,
contact lenses and ophthalmic lenses pg1
Word Components
Word root Combining form Meaning
Ophthalm Ophthalm/o eye
Ocul ocul/o; -ocular eye
Opt opt/o sight
Word Components
Word root Combining form
Meaning
Blephar blephar/o eyelid
Sclera scler/o hard (white of the eye)
kerat kerat/o cornea / horny / epidermis
Ir ir/o, irid/o iris (coloured part of eye that bends regulating amount of light entering eye
Cycl cycl/o ciliary body
The eyeball
2 large cavities separated by the lens of the eye
Anterior Cavity– divided into 2 parts by iris
Is filled with watery fluid called aqueous humor
Posterior Cavity– lies between the lens and retina of the eye
Contains a jelly like substance called the vitreous humor
Word components
Root/prefix/suffix
Combining form
Meaning
goni goni/o peripheral angle of the eye
pupil pupill/o pupil
cor cor/o pupil
choroid choroid/o middle pigmented vascular coat of the posterior section of eyeball
Retin retin/o light sensitive area of eye
Papill papill/o nipple shaped
Word ComponetsRoot/prefix/suffix
Combining form
Meaning
Phak phac/o,phak/o lens of the eye
Scot scot/o, scotoma blindspots of vision
Lacrim (Latin) lacrim/o tear
Dacry (Greek) dacry/o tear or lacriminal apparatus
cili cili/o eyelash
Corne corne/o cornea (transparent circular anterior part of eyeball
cyst cyst/o bladder or sac
-opia condition of vision
Vitre Vitre/o glass pg 3
Layers of the eye
Sclera – outer layer of the eyeball Is the white of the eye covers entire eyeball
except cornea Cornea – transparent protective covering of
the iris Iris – coloured part of the eye and regulates
amount of light entering eye through the pupil Pupil – black hole in the middle of eye pg4
Layers of the eye
Choroid – thin brown layer that lines internal surface of sclera
- is between the retinal and sclera layers Retina – inner layer of the eye
forms images to see colour shades and movements
Lacrimal apparatus provides lubrication with it’s
fluid and drains into the lacrimal sac and enters the nose pg4
Conditions and Terms
Astigmatism vision defect where vision is distorted
Cataract opacity of the lens of the eye
Choroiditis inflammation of layer between retina and sclera
Conjunctivitis inflammation of the conjunctiva
Emmetropia light falls on retina in correct position i.e normal vision
Entropion inward turning of eyelid
Glaucoma abnormal pressure of the fluid in the eye
Hypermetropia long sightedness;light rays are focused beyond retina
Conditions and Terms
Keratitis inflammation of the cornea
Myopia shortsightedness
Nystagmus involuntary movement of eye
Orthoptics pertaining to study and treatment of muscle imbalances of eye i.e.squints
Strabismus squint
Stye inflammation of the gland at base of eyelash
Trichiasis eyelashes rubbing against cornea
Xeropthalmia dry eyes
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