mucous membrane that lines the eyelids and covers the sclera in front

gland located in the upper outer region above the eyeball that secretes tears

passageway for tears from the lacrimal sac into the nose

The outer layer of the eye; the "white of the eye."

middle layer of the eye; contains blood vessels

The inner layer of the eye; light sensitive layer of the eye; contains rods and cones

tiny pit or depression in the retina that is the region of clearest vision

A yellowish area near the center of the back of the retina surrounding the fovea centralis.

The clear tissue that covers the front of the eye

the clear fluid filling the space in the front of the eyeball between the lens and the cornea.

the transparent structure behind the pupil that changes shape to help focus images on the retina

a transparent jellylike substance filling the interior of the eyeball

ring of smooth muscle that changes the shape of the lens within the eye to view objects at different distances

a fibrous membrane that holds the lens of the eye in place

the visible part of the ear; also called the auricle

The ear canal; leads to the tympanic membrane.

The eardrum. A structure that separates the outer ear from the middle ear and vibrates in response to sound waves.

three tiny bones in the middle ear

hammer; first of the three auditory ossicles of the middle ear

anvil; middle of the three auditory ossicles of the middle ear

stirrup; last of the three auditory ossicles of the middle ear

A narrow tube between the middle ear and the throat that serves to equalize pressure on both sides of the eardrum

three fluid-filled canals in the inner ear responsible for our sense of balance

a bony chamber between the semicircular canals and the cochlea

a coiled, bony, fluid-filled tube in the inner ear; sound waves traveling through the cochlear fluid trigger nerve impulses

the corner of the eye, the angle where the lids meet.

Region at the back of the eye where the optic nerve meets the retina. It is the blind spot of the eye because it contains only nerve fibers, no rods or cones.

Retinal receptors that detect black, white, and gray; functions well in dim light

retinal receptor cells that are concentrated near the center of the retina and that function in daylight or in well-lit conditions. The cones detect fine detail and give rise to color sensations.

a photosensitive pigment that lets rods and cones respond to light.

the nerve that carries neural impulses from the eye to the brain; is cranial nerve II

Six muscles attach to the outer surface of the eye and produce eye movements

muscles located inside of the eye; the muscles that help the iris control the amount of light entering the pupil

a condition in which nearby objects are seen more clearly than distant objects because distant objects focus in front of the retina

a condition in which faraway objects are seen more clearly than near objects because the image of near objects is focused behind the retina

the process by which light rays are bent as they pass through the structures of the eye, enabling light from the environment to focus on the retina.

the process by which the eye's lens changes shape to focus near or far objects on the retina

the process by which the pupil changes in size; regulates the amount of light entering the pupil

medial movement of the eyes during focusing on close objects

Center part of the cochlea, containing hair cells, canals, and membranes

a cavity in the temporal bone filled with perilymph

membrane-covered tubes inside the bony labyrinth filled with endolymph

the nerve that carries smell impulses from the nose to the brain; cranial nerve I

sensory receptors that respond to changes in temperature

Sensory receptors, located in the muscles and joints, that provide information about body position and movement.

pain receptors

the nerve that carries impulses from the inner ear to the brain, resulting in the perception of sound; cranial nerve VIII; also called vestibulocochlear nerve