The Sensory Pathways

a. The body is continuously bombarded by types of information called stimuli (stimulus, singular). Those few stimuli which are consciously perceived (in the cerebral hemispheres) are called sensations.

b. Those stimuli received throughout the body are called the general senses. Stimuli received by only single pairs of organs in the head (for example, the eyes) are called special senses (for example, smell and taste).

c. The general senses in humans include pain, temperature (warm and cold), touch (light and deep), and proprioception ("body sense": posture, tone, tension).

d. The special senses in humans include smell (olfaction), taste (gustation), vision, hearing (auditory), and equilibrium.

e. The input from each special sensory receptor goes to its own specific area of the opposite cerebral hemisphere. The general sensory pathway is from the receptor organ, via the PNS nerves, to the CNS. This general pathway then ascends fiber tracts in the neuraxis. The pathway ends in the central area of the cerebral hemisphere (on the side opposite to the input).

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