The curved, transparent, protective layer through which light rays enter the eye.
cornea
A system that translates information from outside the nervous system into neural activity.
sense
A theory suggesting that a functional "gate" in the spinal cord can either let pain impulses travel upward to the brain or block their progress.
gate theory
A psychological dimension of sound determined by the amplitude of a sound wave.
loudness
Our sense of smell
Olfactory
The part of the eye behind the pupil that bends light rays, focusing them on the retina.
lens
The process of converting incoming energy into neural activity.
transduction
The absence of pain sensations in the presence of a normally painful stimulus.
analgesia
How high or low a tone sounds.
pitch
Our sense of taste
gustation
The surface at the back of the eye onto which the lens focuses light rays.
retina
A physical dimension of light waves that refers to how much energy the light contains; it determines the brightness of light.
light intensity
pain from internal organs and is generally described as dull.
visceral pain
A fluid-filled spiral structure in the ear in which auditory transduction occurs.
cochlea
A condition in which lack of certain photopigments leave a person unable to sense certain colors.
color blindness
The colorful part of the eye, which constricts or relaxes to adjust the amount of light entering the eye.
iris
The distance between peaks in light waves.
light wavelength
pain perceived at a location other than the site of the painful stimulus/ origin.
referred pain
The mixture of frequencies and amplitudes that make up the quality of sound.
timbre
Structures on the tongue containing groups of taste receptors, or taste buds.
papillae
A region in the center of the retina where cones are highly concentrated.
fovea
Electromagnetic radiation that has a wavelength of approximately 400 to 750 nm.
visible light
peripheral sensory neurons known as nociceptors alert us to potentially damaging stimuli at the skin by detecting extremes
nociceptors
A repetitive fluctuation in the pressure of a medium, such as air.
sound
A blending of sensory experience that causes some people to "see" sounds or "taste" colors, for example.
synesthesia