Anatomy and Physiology-Chapter 7: The Sensory Systems (All Vocabulary)

Aqueous and vitreous humors

The watery fluid that fills the anterior and posterior chambers of the eye.

Choroid

The middle layer of the wall of the eye.

Ciliary body

The structure between the choroid and the iris that anchors the lens in place.

Ciliary glands

Modified sweat glands located between the eyelashes.

Cones

Sensory cells in the retina that are sensitive to bright light and provide color vision.

Conjunctiva

A delicate external membrane that covers the exposed eyeball and lines the eyelid.

Cornea

A transparent tissue over the anterior center of the eye.

Extrinsic muscles

Muscles attached to the outer surface of the eye that are responsible for changing the direction of viewing.

Iris

The anterior portion of the choroid, which gives the eye its color.

Lacrimal glands

Tear secretors; located above the lateral end of each eye.

Lens

A transparent, flexible structure that is curved outward on both sides.

Optic chiasma

The point at which the optic nerves cross.

Optic nerve

Transmitter of visual sensory signals to the occipital lobe of the brain.

Optic tracts

The continuation of the optic nerve fibers beyond the optic chiasma.

Pupil

The opening through which light rays enter the eye.

Retina

The innermost layer of the eye, containing light-sensitive nerve endings that send impulses through the optic nerve to the brain.

Rods

Sensory cells in the retina that are activated in dim light.

Sclera

The tough, fibrous outer layer of the eye.

Suspensory ligaments

Tiny structures that attach the lens of the eye to the ciliary body.

Tarsal glands

Secretors of an oily substance; located in the eyelids.

Anvil

Tiny bone within the middle ear that transmits sound from the hammer to the stirrup.

Auditory canal

A short, tubelike structure that connects the outer ear to the eardrum.

Auricle

The irregularly shaped outer portion of the ear.

Bony labyrinth

Winding tunnels located in the inner ear.

Ceruminous glands

Secretors of cerumen, or earwax; located in the auditory canal.

Cochlea

A snail-shaped structure in the inner ear that enables one to hear.

Cochlear duct

The portion of the membranous labyrinth inside the cochlea.

Endolymph

A thick fluid inside the membranous labyrinth.

Eustachian tube

A channel that connects the middle ear to the pharynx and serves to equalize pressure on either side of the tympanic membrane.

Hammer

Tiny bone in the middle ear that transmits sound from the tympanic membrane (eardrum) to the anvil.

Membranous labyrinth

Membrane-covered tubes inside the bony labyrinth.

Organ of Corti

A spiral-shaped ridge of epithelium in the cochlear duct lined with hair cells that serve as hearing receptors.

Ossicles

The body’s three smallest bones-the hammer, anvil, and stirrup; found in the middle ear.

Oval window

A membrane-covered opening that connects the middle ear to the inner ear.

Perilymph

A clear fluid that fills the bony labyrinth.

Semicircular canals

Inner ear channels containing receptor hair cells that play an important role in balance.

Stirrup

Tiny bone in the middle ear that attaches to the anvil on one side and the oval window on the other.

Tympanic membrane

A sheet of tissue at the end of the auditory canal; also known as the eardrum.

Vestibule

A chamber in the inner ear that contains the three semicircular canals.

Vestibulocochlear nerve

A cranial nerve comprising the cochlear nerve and the vestibular nerve.

Antihistamines

Medications that work to curb the activity of histamines.

Gustatory cells

Sensory receptors located within taste buds.

Gustatory hairs

Threads that emerge from the gustatory cells.

Histamines

Molecules that trigger a reaction to irritation of the nasal membranes, which produces

Mucous layer

A viscous coating that surrounds the olfactory hairs.

Odor molecules

Tiny airborne particles that trigger the sense of smell.

Olfactory bulb

The thickened end of the olfactory nerve that sends sensory impulses to the olfactory region of the brain.

Olfactory filaments

Fibers in the olfactory nerve that receive impulses from olfactory receptor cells.

Olfactory hairs

Threads that extend from the olfactory receptor cells into the nasal cavity.

Olfactory nerve

A cranial nerve that sends impulses to the olfactory cortex of the brain.

Olfactory receptor cells

The sensors responsible for smell.

Olfactory region

A dime-sized area at the top of each nasal cavity that houses sensors responsible for smell.

Papillae

Tiny bumps on the tongue that house taste buds.

Septum

The structure made of cartilage that divides the left and right air passages in the nose.

Tastants

Compounds that stimulate the gustatory hairs to send nerve impulses to the brain.

Taste buds

Sensory receptors for taste.

Taste pores

Very small openings in the top of the taste buds through which gustatory hairs project.