eye and ear anatomy function

• Sclera

• Protects and shapes eyeball

Cornea

• Contributes to blinking and has a lot of pain receptors

• Choroid

• Supplies blood to outer third of photoreceptors

• Ciliary body

• Controls shape of lens

• Iris

• Regulates the amount of light entering the eye

• Pupil

lets light enter the eye

• Lens

• Changes shape to focus light on the retina

• Anterior chamber

• Maintains eye pressure and nourishing internal eye structures

• Posterior chamber

• Transmits light 

• Vitreous cavity

• provides nutrients to your eye and helps your eye keep its shape

• Retina

• Contains photoreceptors and sends signals to the brain

• Optic nerve

• lets your eyes send signals to your brain describing what they detect

• Optic disc (blind spot)

• Site where optic nerves leave the eye

• Macula lutea

• Contains the fovea centralis, which contains all of the cones

Ora serrata

• marks the transition from the simple non-photosensitive area of the retina to the complex, multi-layered photosensitive region

• Lacrimal gland

• Secretes lacrimal secretion (tears)

• Conjunctiva

• Produces a lubricaiting mucous secretion

• Eyebrow

• Shade eyes from sunlight

• Palpebrae/eyelash

• Protects eye from foreign objects and spreads secretion to moisten eye

• Auricle:

collects sound waves

• External auditory meatus/canal:

• Collects sound waves

Tympanic membrane:

• Separates external ear from middle ear

• Eustachian tube

• Equalizes ear pressure

• Auditory ossicles: 

• Malleus

  • relay the vibrations of the incoming soundwaves produced by the eardrum to the incus

• Incus

  • transmits vibrations from the malleus to the stapes

• Stapes

  • transmits sound vibrations from the incus to the oval window

• Cochlea 

hearing

• Vestibule 

• to detect changes in gravity and linear acceleration.

• Semicircular canals

equilibrium

• Organ of Corti

auditory transduction

• Hair cells

• convert mechanical energy into electrical energy transmitted to the central nervous system via the auditory nerve to facilitate audition

• Tectorial membrane:

• Stimulates hair cells

• Basilar membrane: 

supports spiral organ

• Cranial Nerve VIII: Vestibulocochlear

• Balance and hearing

• Oval window

• movement of fluid within the cochlea and activation of receptors for hearing

• Round window 

• decompress acoustic energy that enters the cochlea via stapes movement against the oval window

• Scala vestibule:

• Abuts oval window; contains perilymph

• Scala tympani:

• Terminates at round window contains perilymph

• Cochlear duct

• Houses spiral organ of corti

• Utricle & Saccule

• Detects equilibrium