Unit 4 - Eyeball and Ear

sclera

white of eye, provides shape

cornea

clear covering

vascular tunic

iris, ciliary body, choroid

iris

colored part, controls pupil size

miosis: pupil constriction

mydrosis: pupil dilation

ciliary body

makes aq humor

retina

site of photoreceptors, cones/rods

macula, lutea

fovea centralis, all cones, sharp vision

lens

changes shape of lens to focus on incoming light

when far away..

ciliary muscle relaxes

suspensory ligaments taut

lens thins, flattens

when close up..

ciliary muscle contract

suspensory ligament relaxed

lens thickens, round

aq humor

secreted by ciliary body into anterior chamber

nutrients + o2

vitreous humor

posterior cavity

maintains shape

sequence of light through eye

1. cornea

2. anterior chamber

3. pupil

4. posterior chamber

5. lens

6. vitreous humor

7. retina

8. vascular tunic

external ear

auricle/pinna

external acoustic meatus

auricle/pinna

collects sound waves

external acoustic meatus

conveys sound waves

middle ear

tympanic membrane

maleus, incus, stapes (auditory ossicles)

eustachian tube

inner ear

semicircular canals

cochlea

vestibule

auditory ossicles

amplify, convey sound waves to inner ear

inner ear: balance

utricle, saccule (vestibule)

semicircular canals