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 membrane that LINES THE EYELIDS AND COVERS THE FRONT OF THE EYE to provide additional protection and lubrication.
LENS
A CIRCULAR STRUCTURE LOCATED BEHIND THE PUPIL and suspended in position by ligaments.
REFRACTS
BENDS light rays. (The aqueous humor and lens refract light rays).
VESTIBULE
The FIRST SECTION OF THE INNER EAR, located between the cochlea and the semicircular canals.
AUDITORY CANAL
Also called the EXTERNAL AUDITORY MEATUS, it is a CANAL THAT PROTECTS THE EAR
CORNEA
A CIRCULAR, TRANSPARENT PART OF THE FRONT OF THE SCLERA. It allows light rays to enter the eye.
ORGAN OF CORTI
The RECEPTOR OF SOUND WAVES within the cochlea. It transmits the impulses from sound waves to the auditory nerve.
RETINA
The INNERMOST LAYER OF THE EYE that contains nerve cells and photoreceptors (rods and cones), which pick up light rays (image) and transmit them to the optic nerve.
VITREOUS HUMOR
The JELLYLIKE SUBSTANCE that fills the area behind the lens. It helps maintain the shape of the eyeball and also refracts light rays.
AURICLE
Another name for the PINNA (the visible part of the ear).
EUSTACHIAN TUBE
A canal that CONNECTS THE MIDDLE EAR TO THE PHARYNX (THROAT). It allows air pressure on both sides of the tympanic membrane to be equalized.
OSSICLES
The three small bones in the middle ear: the MALLEUS (hammer), INCUS (anvil), and STAPES (stirrup).
SCLERA
The OUTERMOST LAYER OF THE EYE, often referred to as the "WHITE" OF THE EYE.
CHOROID COAT
The middle layer of the eye, which is a DELICATE MEMBRANE
IRIS
The COLORED PORTION OF THE EYE, located behind the cornea on the front of the choroid coat.
PINNA
The VISIBLE PART OF THE EXTERNAL EAR, composed of elastic cartilage. It directs sound waves into the auditory canal.
SEMICIRCULAR CANALS
Three small, delicate tubes in the inner ear that contain FLUID AND HAIRLIKE CELLS to help maintain BALANCE AND EQUILIBRIUM.
COCHLEA
Shaped like a SNAIL SHELL, it contains the delicate, hairlike ORGAN OF CORTI and transmits the impulses from sound waves to the auditory nerve.
LACRIMAL GLANDS
Glands that PRODUCE TEARS which constantly moisten and cleanse the eye.
PUPIL
The OPENING IN THE CENTER OF THE IRIS which regulates the amount of light that enters the eye.
TYMPANIC MEMBRANE:
Also known as the EARDRUM, it separates the external ear from the middle ear and VIBRATES WHEN SOUND WAVES HIT IT to transmit the waves to the middle ear.