Key Term
aqueous humor
The aqueous humor is a clear, watery fluid that fills the space between the cornea and iris.
conjunctiva
lines the eyelids and covers the front of the eye to provide additional protection and lubrication.
len
The lens is a circular structure located behind the pupil and suspended in position by ligaments
refracts
It 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
the narrow, S-shaped passage in the outer ear that connects the outside world to 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.
auricle
the auricle is the visible, outer part of the ear, also called the pinna. Its function is to collect and funnel sound waves into the ear canal, where they travel toward the eardrum.
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 malleus, the incus, and the stapes. The bones are connected and transmit sound waves from the tympanic membrane to the inner ear.
sclera
The sclera maintains the shape of the eye
choroid coat
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.
pinna
The pinna is elastic cartilage covered by skin.
semicircular canals
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,
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.