Ch. 7.7 Special Senses Key Terms
a clear, watery fluid that fills the space between the cornea and iris and it helps maintain the forward curvature of the eyeball and refracts light rays
aqueous humor
mucous membrane and lines the eyelids and covers the front of the eye to provide additional protection and lubrication
conjunctiva
a circular structure located behind the pupil and suspended in position of ligaments
lens
(bends) light rays so the rays focus on the retina
refracts
first section of the inner ear that acts as the entrance to the two other parts
vestibule
special glands in this canal produce cerumen, a wax that protects the ear
auditory canal
a circular, transparent part of the front of the sclera and allows light rays to enter the eye
cornea
receptor of sound waves located in the cochlea. It transmits impulses from sound waves to the auditory nerve
organ of corti
the innermost layer of the eye, and it is made of many layers of nerve cells, which transmit the light impulses to the optic nerve
retina
the jellylike substance that fills the area behind the lens, which helps maintain the shape of the eyeball, and also refracts light rays, and is a series of muscles located in the eye provided for the eye movement
vitreous humor
the outer ear contains the visible part of the ear
auricle
tube that connects the middle ear to the pharynx and helps equalize air pressure on both sides of the tympanic membrane
eustachian tube
small bones in the middle ear—the malleus, incus, and stapes—that transmit sound waves from the tympanic membrane to the inner ear
ossicles
the outermost layer is the tough connective tissue and is frequently referred to as the “white” of the eye
sclera
the middle layer of the eye, and is interlaced with many blood vessels that nourish the eyes
choroid coat
the colored portion of the eye and is located behind the cornea on the front of the choroid coat
iris
elastic cartilage covered by skin and it leads to a canal, or tube, called the external auditory meatus
pinna
structures in the inner ear that contain liquid and hairlike cells that bend with head and body movements, helping maintain equilibrium
semicircular canals
snail-shaped portion of the inner ear that contains the organ of Corti, which transmits impulses from sound waves to the auditory nerve
cochlea
in the eye produce tears, which constantly moisten and cleanse the eye, and the tears flow across the eye and drain through the nasolacrimal duct into the nasal cavity
lacrimal glands
opening in the center of the iris that allows light to enter
pupil
the eardrum and it separates the outer ear from the middle ear and vibrates when sound waves hit it
tympanic membrane