Ch. 7.7 Special Senses Key Terms
A clear, watery fluid that fills the space between the cornea and the iris (anterior chamber) and the space between the iris and the lens (posterior chamber). It helps nourish the cornea and lens and maintain the shape of the anterior part of the eye.
Aqueous humor
A thin, transparent mucous membrane that covers the inner surface of the eyelids and the white part of the eyeball (sclera). It helps to lubricate and protect the eye.
Conjunctiva
A transparent, biconvex structure located behind the iris and pupil. It changes shape (accommodation) to precisely focus light rays onto the retina.
Lens
In the context of the eye, this term means to bend light rays as they pass through different mediums (like the cornea and lens) so they can be accurately focused onto the retina.
Refracts
The central part of the bony labyrinth in the inner ear, located between the cochlea and the semicircular canals. It contains the utricle and saccule, which are sensory organs responsible for detecting linear acceleration and gravity (static balance).
Vestibule
Also known as the external acoustic meatus, it's a tube that runs from the outer auricle to the tympanic membrane (eardrum) and channels sound waves to the middle ear.
Auditory canal
The transparent, dome-shaped outer layer at the very front of the eye that covers the iris, pupil, and anterior chamber. It is the primary structure that refracts (bends) light entering the eye.
Cornea
The sensory organ for hearing, located within the cochlea of the inner ear. It contains hair cells that convert fluid vibrations into nerve signals.
Organ of Corti
The light-sensitive inner layer at the back of the eye. It contains photoreceptor cells (rods and cones) that convert focused light into neural signals, which are sent to the brain.
Retina
A clear, jelly-like substance that fills the large space behind the lens (vitreous cavity). It helps maintain the spherical shape of the eyeball.
Vitreous humor
The visible, cartilaginous part of the outer ear on the side of the head; also known as the pinna (see number 14). It functions to collect and funnel sound waves.
Auricle
A narrow canal that connects the middle ear cavity to the nasopharynx (the upper throat and back of the nasal cavity). Its function is to equalize pressure between the middle ear and the atmosphere.
Eustachian tube
A chain of three tiny bones (malleus, incus, and stapes) in the middle ear. They transmit sound vibrations from the tympanic membrane (eardrum) to the oval window of the cochlea.
Ossicles
The tough, fibrous, white outer layer that covers most of the eyeball. It provides protection and maintains the shape of the eye.
Sclera
The middle layer of the eye wall, situated between the retina and the sclera. It is rich in blood vessels, supplying oxygen and nourishment to the outer layers of the retina.
Choroid coat
The colored, muscular part of the eye, located behind the cornea and in front of the lens. It controls the size of the pupil to regulate the amount of light reaching the retina
Iris
Another term for the auricle (see number 3), the visible, external part of the ear
Pinna
Three fluid-filled, bony canals in the inner ear, oriented at right angles to each other. They detect head rotation and movement, playing a crucial role in balance and equilibrium.
Semicircular canals
A spiral-shaped, bony structure in the inner ear containing the Organ of Corti (see number 12). It is responsible for converting sound vibrations into nerve impulses.
Cochlea
Glands located above the outer corner of each eye that secrete tears (a watery, lubricating fluid) to moisten, nourish, and protect the surface of the eye.
Lacrimal glands
he dark, circular opening in the center of the iris that allows light to enter the eye. Its size is controlled by the iris.
Pupil
Commonly called the eardrum, a thin, cone-shaped membrane that separates the auditory canal (outer ear) from the middle ear. It vibrates when struck by sound waves.
Tympanic membrane