Lab - Eye & Ear Anatomy

conjunctiva

mucous membrane covering the sclera, but not the cornea

pupil

black hole in the center of the iris

aqueous humor

watery fluid in the anterior chamber that provides

vitreous humor

jelly-like substance that fills the vitreous chamber between the lens and retina

sclera

outermost layer of the eye

cornea

anterior portion of the eye allowing light to enter

iris

colored portion of the external eye

lens

transparent, biconvex-shaped

choroid

dark brown, lots of melanin, rich in blood vessels

absorbs excess light

suspensory ligaments or zonular fibers

attach lens to ciliary body

ciliary body

made of smooth involuntary muscles

contraction changes thickness of lens

retina

light-sensitive innermost layer of the eye

photoreceptors

rods & cones

responsible for converting light into electrical signals

rods

dim light vision, distinguish shades

cylindrical

cones

bright light vision, color vision

conical

optic disc

blind spot

where the nerve fibers of the photoreceptors communicate with the optic nerve

fovea centralis

pit-like depression in the retina

high concentration of cones

macula lutea

oval-shaped area located in the central of the retina at the back of the eye

auricle

reinforced with elastic cartilage

visible outer part of the ear

external auditory meatus

ear canal

tympanic membrane

eardrum

vibrates

ossicles

middle bone

malleus, incus, stapes

malleus

hammer

incus

anvil

stapes

Connects ossicles to vestibule

cochlea

snail’s shell

contains sensory receptors for sound

vestibule

oval window

where stapes connect to vestibule

pharyngotympanic tube

auditory tube or Eustachian tube

vestibular branch

part of the vestibulocochlear nerve that connects to the vestibule

cochlear branch

part of the vestibulocochlear nerve that connects to the cochlea

semicircular ducts

fluid-filled tubes branching off the vestibule

aid in balance or sense of equilibrium

ampulla

enlarged portion of each of the semicircular ducts