| accomodation | adjustment of lens of eye for close or distant vision |
| ampulla | an expansion at the end of each semicircular canal that contains a crista ampullaris |
| chemoreceptor | a receptor that is stimulated by the binding of certain chemicals |
| cochlea | portion of inner ear that contains hearing receptors |
| dynamic equilibrium | maintenance of balance when the head and body are suddenly moved or rotated |
| labyrinth | the system of connecting tubes within the inner ear, including cochlea, vestibule, and semicircular canals |
| macula lutea | a yellowish depression in the retina of the eye that is associated with acute vision |
| mechanoreceptor | a sensory receptor that senses mechanical stimulation, such as changes in pressure or tension |
| pain receptor | sensory nerve ending associated with the feeling of pain |
| photoreceptor | a sensory receptor sensitive to light energy; rods and cones |
| projection | process by which the brain causes a sensation to seem to come from the region of the body being stimulated |
| referred pain | pain that feels as if it is originating from a part other than the site being stimulated |
| refraction | a bending of light as it passes between media of different densities |
| retina | inner layer of the eye wall that contains the visual receptors |
| rhodopsin | light-sensitive pigment in the rods of the retina; visual purple |
| sclera | white, fibrous outer layer of the eyeball |
| sensory adaptation | sensory receptors becoming less responsive after constant repeated stimulation |
| static equilibrium | the maintenance of balance when the head and body are motionless |
| thermoreceptor | a sensory receptor sensitive to temperature changes; heat and cold receptors |