ORGANS OF SENSES: Words to Know


Aqueous humor

Tissue fluid filling the cavity of the eye between the cornea and the lens.

Ceruminous glands

Exocrine glands in the skin of the auditory canal of the ear that secrete earwax (cerumen).

Chemoreceptors

Receptors sensitive to various chemicals substances.

Choroid

Middle, pigmented layer of the eye.

Ciliary body

Circular muscle that surrounds the edge of the lens of the eye and changes the shape of the lens.

Cochlea

Spiral-shaped cavity in the inner ear that contains the receptors for hearing in the organ of
Corti.

Cones

Photoreceptors in the retina of the eye that detect colours.

Cornea

Transparent front part of the sclera of the eye.

Conjunctiva

Mucous membrane lining the eyelids and covering the front surface of the eyeball.

Eardrum

Thin membrane at the end of the outer ear that vibrates when sound waves strike it.

Eustachian tube

Slender air passage between the middle ear cavity and the pharynx, which equalizes air pressure on
the two sides of the eardrum.

External auditory canal

Also called the ear canal, the tunnel in the ear between the pinna and eardrum.

Gustatory cells

Chemoreceptors located within taste buds.

Iris

Pigmented (colored) part of the eye between the cornea and lens made of two sets of smooth muscle
fibers.

Lacrimal gland

Gland located at the upper, outer corner of each eyeball that secretes tears.

Lens

Clear, oval, flexible structure behind the pupil in the eye that changes shape for the focusing of
light rays.

Mechanoreceptors

Receptors sensitive to mechanical or physical pressures such as sound and touch.

Olfactory epithelium

Section of mucous membrane in the roof of the nasal cavity that contains odor-sensitive olfactory
nerve cells.

Organ of Corti

Structure in the cochlea of the inner ear that contains the receptors for hearing.

Ossicles

Three bones of the middle ear: hammer, anvil, and stirrup.

Papillae

Projections on the tongue that contain taste buds.

Photoreceptors

Receptors sensitive to light.

Pinna

Commonly referred to as the ear, the outer, flaplike portion of the ear.

Pupil

Opening in the center of the iris though which light passes.

Retina

Innermost layer of the eyeball that contains the photoreceptors—the rods and cones.

Rods

Photoreceptors in the retina of the eye that detect the presence of light.

Sclera

Outermost layer of the eyeball, made of connective tissue.

Semicircular canals

Three oval canals in the inner ear that help to maintain balance.

Taste buds

Structures on the papillae of the tongue that contain chemoreceptors that respond to chemicals
dissolved in saliva.

Utricle

Membranous sac in the vestibule of the inner ear that contains receptors for the sense of balance.

Vestibule

Bony chamber of the inner ear that contains the utricle and the saccule (the smaller of two
membranous sacs in the vestibule of the inner ear).

Vitreous humor

Transparent, gellike substance that fills the cavity of the eye behind the lens.



Words necessary to know.



Words not necessary to know.