Download Inner ear

Survey
yes no Was this document useful for you?
   Thank you for your participation!

* Your assessment is very important for improving the work of artificial intelligence, which forms the content of this project

Document related concepts

Human eye wikipedia, lookup

Eyeglass prescription wikipedia, lookup

Dry eye syndrome wikipedia, lookup

Cataract wikipedia, lookup

Contact lens wikipedia, lookup

Keratoconus wikipedia, lookup

Blast-related ocular trauma wikipedia, lookup

Idiopathic intracranial hypertension wikipedia, lookup

Vision therapy wikipedia, lookup

Cataract surgery wikipedia, lookup

Photoreceptor cell wikipedia, lookup

Visual impairment due to intracranial pressure wikipedia, lookup

Retina wikipedia, lookup

Corneal transplantation wikipedia, lookup

Visual impairment wikipedia, lookup

Diabetic retinopathy wikipedia, lookup

Trachoma wikipedia, lookup

Transcript
SENSES (EYE & EAR) &
INTERGUMENTARY SYSTEM
(SKIN)
The Senses
General Senses

Distributed throughout body





Pain
Touch
Pressure
Temperature
Proprioception
Special Senses






Located within complex sense organs
Gustation = sense of taste
Olfaction = sense of smell
Hearing
Equilibrium
Vision
The Ear


Used for both hearing and equilibrium
Divided into three parts

Outer ear


Pinna (auricle)
External auditory canal (meatus)


Contains cerumen (earwax)
Tympanic membrane (eardrum)

Transmits sound waves to middle ear
The Ear (con’t)

Middle ear

Houses three ossicles



Malleus (hammer)
Incus (anvil)
Stapes (stirrup)
Soundwaves are transmitted from footplate of
stapes
Eustachian tube




Connects middle ear to nasopharynx
Equalizes pressure between outer and middle ear
The Ear (con’t)

Inner ear





Complex labyrinth shape
Filled with fluid
Contains cochlea
 Organ of Corti
Vestibular apparatus
 Sense of equilibrium
 Semicircular canals
Vestibulocochlear nerve
 Cochlear branch transmits hearing impulses
 Vestibular branch transmits equilibrium impulses
Otitis

Inflammation of the ear

Otitis media = infection leading to accumulation of
fluid in middle ear

Causes



Obstruction of eustachian tube caused by
Spreading infection
Treatment


Antibiotics
Myringotomy
Otitis (con’t)

Otitis externa



Inflammation of external auditory canal
Also known as “swimmer’s ear”
Caused by:



Fungus
Bacterium
Common among:


People living in hot climates
Swimmers
Meniere Disease


Involves production and circulation of inner ear fluid
Symptoms





Vertigo (dizziness)
Hearing loss
Tinnitus (ringing in ears)
Pressure
Treatment


Drugs (to treat nausea and dizziness)
Severe cases
 Inner ear or eighth cranial nerve destroyed surgically
The Eye and Vision

Eye has three layers

Sclera
 Outermost layer
 Known as “White of the eye”
 Extends over front of eye as transparent cornea
Uvea

Uvea


Middle, vascular layer
Consists of:


Choroid
Ciliary body



Muscle controls shape of lens
Allows for accommodation
Iris



Muscular ring
Controls size of pupil
Determines eye color
Retina



Innermost layer
Actual visual receptor
Consists of specialized cells:

Rods




Function in dim light
Low visual acuity
Do not respond to color
Cones



Active in bright light
High visual acuity
Respond to color
Eye Protection


Orbit = bony socket
Eyelids





Conjunctiva
 Thin membrane
 Covers anterior portion of eye
Eyebrows
Eyelashes
Tears
Lacrimal glands


Bathe eyes with lubricating fluid
Fluid drains into nose
Errors of Refraction

Myopia = nearsightedness



Hyperopia = farsightedness




Eyeball too long
Images form in front of retina
Eyeball too short
Images form behind retina
Astigmatism = irregularity in curve of cornea or
lens
Glasses can correct most of these impairments
Infection

Conjunctivitis = inflammation of conjunctiva



Trachoma = inflammation of cornea and
conjunctiva



Commonly known as “pinkeye”
Highly infectious
Results in scarring
Common cause of blindness in 3rd world countries
Ophthalmia neonatorum = acute conjunctivitis in
newborns

Caused by gonorrhea
Disorders of Retina

Retinal detachment
 Separation of retina from choroid
 Caused by:




Tumor
Hemorrhage
Injury to eye
Repaired with laser surgery
Cataract

Opacity of lens caused by:





Disease
Injury
Chemicals
Exposure to UV rays
Must be removed to prevent blindness


Anterior capsule removed
Phacoemulsification
Glaucoma






Increased pressure within eyeball
More aqueous humor produced than can be
drained away
Leads to blindness
Many causes
Screening at routine eye exams
Treatment


Medication
Surgery
Integumentary system: THE
SKIN, NAILS, & HAIR