50-4 Sensory System

iris

a flat, colored, ring-shaped membrane behind the cornea of the eye

thermoreceptors

a kind of sensory receptor that responds to changes in temperature

chemoreceptors

a kind of sensory receptor that responds to chemicals

mechanoreceptors

a kind of sensory receptor that responds to movement, pressure, and tension

pain receptors

a kind of sensory receptor that responds to tissue damage

photoreceptors

a kind of sensory receptor that responds to variations in light

amygdala

a limbic structure in the brain that is important to emotion, memory, eating behaviors

oval window

a membrane that separates the middle ear from the inner ear

lens

after light travels through the pupil, it enters __, a convex crystalline structure; bends the rays of the incoming light

tympanic membrane

also known as the eardrum

eustachian tube

an opening in the throat that enables you to equalize the pressure on both sides of your tympanic membrane whenever you experience a sudden change in air pressure

optic nerve

carries visual information in the form of action potentials from the retina to the thalamus

auditory canal

connects the external ear with the tympanic membrane

cones

help translate light energy into electrical signals that can be interpreted by the brain; __ are stimulated by bright lights; allows you to see all colors of the visible spectrum

rods

help translate light energy into electrical signals that can be interpreted by the brain; __ respond to dim light

sense organs

include the eyes, ears, nose, mouth, and skin

cornea

light first passes through here; a clear protective layer

cochlea

located in the inner ear; a coiled tube consisting of three fluid-filled chambers that are separated by membranes

papillae

most taste buds are in between these bumps on the tongue

olfactory receptors

specialized chemoreceptors located in the olfactory epithelium of the nasal passage

taste buds

the chemoreceptors for taste

retina

the light-sensitive inner layer of the eye; where the light focuses

pupil

the opening to the interior of the eye

organ of Corti

the organ of hearing; rests on the bottom membrane in cochlea and has sensory receptors called hair cells, which move and stimulate action potentials

semi-circular canals

these canals in the inner ear are filled with fluid and lined with hair cells that help maintain balance of the body