Ch. 7.7 Special Senses Key Terms
Aqueous Humor
A clear, watery fluid that fills the space between the cornea and the iris
Conjunctiva
A thin, transparent membrane covering the inner surface of the eyelids and the front of the sclera.
Lens
A transparent, biconvex structure behind the iris that changes shape to fine-tune the focusing of light onto the retina.
Refracts
The action of light being bent or changed in direction, mainly by the cornea and lens, to focus an image.
Vestibule
The central chamber of the inner ear, responsible for detecting linear acceleration and maintaining static balance.
Auditory Canal
The tube connecting the auricle (pinna) to the tympanic membrane (eardrum) that conducts sound waves.
Cornea
The transparent, dome-shaped outer layer at the very front of the eye; it is the primary structure that refracts (bends) light.
Organ of Corti
The actual sensory organ of hearing, located inside the cochlea, containing hair cells that convert sound vibrations into nerve impulses.
Retina
The light-sensitive layer at the back of the eye that contains photoreceptor cells (rods and cones) and converts light into electrical signals.
Auricle
The visible, fleshy outer part of the ear attached to the side of the head that collects sound waves.
Eustachian Tube
A tube connecting the middle ear to the throat (nasopharynx); it equalizes air pressure across the eardrum.
Ossicles
The three tiny bones (malleus, incus, stapes) in the middle ear that transmit and amplify sound vibrations from the eardrum to the inner ear.
Sclera
The tough, opaque white outer layer of the eyeball that provides protection and maintains the eye's shape.
Choroid Coat
The middle, highly vascular (blood vessel-rich) layer of the eye that supplies oxygen and nutrients to the outer layers of the retina.
Iris
The colored, muscular part of the eye that surrounds the pupil and controls the amount of light entering the eye.
Pinna
The external, visible part of the ear that collects and funnels sound waves.
Semicircular Canals
Three fluid-filled loops in the inner ear that are responsible for detecting rotational movements and maintaining dynamic balance.
Cochlea
The spiral-shaped, bony, fluid-filled structure in the inner ear that contains the sensory organ of hearing.
Lacrimal Glands
Glands that produce tears to moisten, cleanse, and protect the surface of the eye.
Pupil
The adjustable opening in the center of the iris through which light enters the inner eye.
Tympanic Membrane (Eardrum)
A thin membrane that vibrates in response to sound waves, separating the outer ear from the middle ear.