Ch. 7.7 Special Senses Key Terms
A clear, watery fluid that fills the space between the cornea and iris.
aqueous humor
A mucous membrane that lines the eyelids and covers the front of the eye to provide additional protection and lubrication.
conjuctiva
A circular structure located behind the pupil that refracts (bends) light rays so they focus on the retina.
lens
Bends (light rays).
refracts
The first section of the inner ear, which acts as the entrance to the cochlea and semicircular canals.
vestibule
A canal, or tube, in the outer ear that sound waves travel through; also called the external auditory meatus.
auditory canal
A circular, transparent part of the front of the sclera that allows light rays to enter the eye.
cornea
A receptor of sound waves (located in the cochlea) that transmits impulses from sound waves to the auditory nerve.
organ of corti
The innermost layer of the eye, made of many layers of nerve cells (including rods and cones), which transmit light impulses to the optic nerve.
retina
The jellylike substance that fills the area behind the lens, helping to maintain the shape of the eyeball and refract light rays.
vitreous humor
The visible part of the ear; also called pinna.
auricle
A tube that connects the middle ear to the pharynx (throat) and helps equalize air pressure on both sides of the tympanic membrane.
eustachian tube
Three small bones in the middle ear (malleus, incus, and stapes) that are connected and transmit sound waves.
ossicles
The outermost layer of the eye; the tough connective tissue often referred to as the "white" of the eye that maintains the eye's shape.
sclera
: The middle layer of the eye, which is interlaced with many blood vessels that nourish the eyes.
choroid coat
The colored portion of the eye that contains two muscles which control the size of the pupil
iris
The visible part of the ear; also called auricle.
pinna
Canals in the inner ear that contain liquid and hairlike cells; impulses sent from them help maintain balance and equilibrium.
semicircular canals
Shaped like a snail's shell, it is part of the inner ear that contains the organ of Corti.
cochlea
Glands in the eye that produce tears, which constantly moisten and cleanse the eye
lacrimal glands
The opening in the center of the iris.
pupil
The eardrum; it separates the outer ear from the middle ear and vibrates when sound waves hit it.
tympanic membrane