Eye and Ear Anatomy

Flashcards for eye and ear anatomy and function.

Lacrimal gland

Production of tears

Sclera

Outer, whitish, protective layer

Cornea

Outer, transparent layer, refracts light

Choroid

Middle, vascular layer of eye, pigmented brown

Iris

Smooth muscle here controls pupil diameter

Pupil

Opening that allows light to enter eye

Ciliary body

Produces aq. humor; sm. muscle to change lens shape

Ciliary zonule (suspensory ligaments)

Attach lens to ciliary muscle

Lens

Changes shape

Vitreous body

Maintains shape of eye, stabilizes retina

Retina

Neural layer, contains photoreceptors, rods and cones

Optic nerve (CN II)

SS - vision from retina

Optic disc

All axons, no photoreceptors = blind spot

Macula lutea

Contains fovea centralis, highest conc. of cones

Auricle (pinna)

Funnels pressure waves to external auditory canal

External auditory canal

Conducts pressure waves to eardrum (tympanic membrane)

Tympanic membrane

Coverts pressure waves to mechanical vibration

Malleus

Transmits vibrations from tympanic membrane to incus

Incus

Transmits vibrations from malleus to stapes

Stapes

Transmits vibrations from incus to oval window

Auditory (Eustachian) tube

Connects middle ear to pharynx; equalize air pressure

Cochlea

Contains the spiral organ (of Corti) for hearing

Vestibule

Bony cavity houses utricle and saccule

Utricle

Contains otolith organ and hair cells for sensing acceleration

Saccule

Contains otolith organ and hair cells for sensing acceleration

Semicircular canal(s)

Contains cupula(e) and hair cells for sensing rotational movement

Vestibulocochlear nerve (CN VIII)

SS - balance (vestibular) and hearing (cochlear)

Vestibular branch

SS - balance from vestibule and semicircular canals

Cochlear branch

SS- hearing from cochlea

Vestibular duct (scala vestibuli)

Transmits pressure waves from oval window to apex of cochlea

Vestibular membrane

Vibrates to transmit pressure waves to cochlear duct

Cochlear duct (scala media)

Endolymph filled cavity, contains spiral organ (of Corti)

Tympanic duct (scala tympani)

Transmits pressure waves from apex of cochlea to round window

Spiral organ (of Corti)

Special sensory organ of hearing, contains hair cells

Inner hair cells

Transduce pressure waves into action potentials

Outer hair cells

Amplify membrane vibrations to enhance hearing sensitivity

Supporting cells

Provide stability and metabolic support to hair cells

Tectorial membrane

Interact with hair cell stereocilia

Basilar membrane

Oscillates in response to pressure waves

Spiral ganglion

Bipolar cells form the cochlear branch of CN VIII

Cochlear nerve

SS- hearing from cochlea

Perilymph

Fluid found in vestibular and tympanic duct

Endolymph

High K+ ion fluid found in cochlear duct