Anatomy => Sense Organs
Sense Organs, in humans and other animals, faculties by which outside information is received for evaluation and response. This is accomplished by the effect of a particular stimulus on a specialized organ, which then transmits impulses to the brain via a nerve or nerves.
Aristotle classified five senses: hearing, sight, smell, taste, and touch, the last of which has a multiplicity of subdivisions, including the senses of pressure, heat, cold, contact, and pain. These have continued to be regarded as the classical five senses, although scientists have determined the existence of as many as 15 additional senses. Sense organs buried deep in the tissues of muscles, tendons, and joints, for example, give rise to sensations of weight, position of the body, and amount of bending of the various joints; these organs are called proprioceptors. Within the semicircular canal of the ear is the organ of equilibrium, concerned with the sense of balance. General senses, which produce information concerning bodily needs (hunger, thirst, fatigue, and pain), are also recognized.
See also Ear; Eye; Hearing; Mouth; Nervous System; Nose; Skin; Smell; Taste; Tongue; Touch; Vision.