Key Words
aqueous humor
“A clear, watery fluid that fills the space between the cornea and iris. It helps maintain the forward curvature of the eyeball and refracts light rays.”
conjunctiva
“A mucous membrane, called the conjunctiva, lines the eyelids and covers the front of the eye to provide additional protection and lubrication.”
lens
“The lens is a circular structure located behind the pupil and suspended in position by ligaments. It refracts light rays so the rays focus on the retina.”
refracts
“Refracts (bends) light rays so the rays focus on the retina.”
vestibule
“The first section is the vestibule, which acts as the entrance to the two other parts of the inner ear.”
auditory canal
“A canal, or tube, called the external auditory meatus, or auditory canal. Sound waves travel through the auditory canal until they reach the eardrum.”
cornea
“The cornea is a circular, transparent part of the front of the sclera. It allows light rays to enter the eye.”
organ of Corti
“The organ of Corti transmits the impulses from sound waves to the auditory nerve.”
retina
“The innermost layer of the eye is the retina. It is made of many layers of nerve cells, which transmit the light impulses to the optic nerve.”
vitreous humor
“The vitreous humor is the jellylike substance that fills the area behind the lens. It helps maintain the shape of the eyeball and also refracts light rays.”
auricle (pinna)
“The outer ear contains the visible part of the ear, called the pinna, or auricle. The pinna is elastic cartilage covered by skin.”
eustachian tube
“This tube allows air to enter the middle ear and helps equalize air pressure on both sides of the tympanic membrane.”
ossicles
“The middle ear contains three small bones (ossicles): the malleus, the incus, and the stapes. The bones are connected and transmit sound waves from the tympanic membrane to the inner ear.”
sclera
“The outermost layer is the tough connective tissue called the sclera. It is frequently referred to as the ‘white’ of the eye. The sclera maintains the shape of the eye.”
choroid coat
“The middle layer of the eye, the choroid coat, is interlaced with many blood vessels that nourish the eyes.”
iris
“The iris is the colored portion of the eye. It is located behind the cornea on the front of the choroid coat.
The iris contains two muscles, which control the size of the pupil and regulate the amount of light entering the eye.”
pinna (auricle)
“The outer ear contains the visible part of the ear, called the pinna, or auricle.”
semicircular canals
“Semicircular canals are also located in the inner ear. These canals contain a liquid and delicate, hairlike cells that bend when the liquid moves with head and body movements. Impulses sent from the semicircular canals to the cerebellum of the brain help to maintain our sense of balance and equilibrium.”
cochlea
“The cochlea, shaped like a snail’s shell, contains delicate, hairlike mechanoreceptor cells, which compose the organ of Corti, a receptor of sound waves.”
lacrimal glands
“Lacrimal glands in the eye produce tears, which constantly moisten and cleanse the eye.”
pupil
“The opening in the center of the iris is called the pupil.”
tympanic membrane
“The tympanic membrane separates the outer ear from the middle ear. It vibrates when sound waves hit it and transmits the sound waves to the middle ear.”