Sensory Reception - Abstract and Review

Sensory  reception is the means by which an organism is able to react
to changes in its external or internal environment, in particular through
the activation of specific parts, which transform the energy change involved into
vital processes. In many instances, environmental changes are transmitted from
the receptor organ to other parts of the body by
specialized cells, but in unicellular organisms such transformations are
made by specialized organelles, such as light-sensitive "eye spots" or cilia
sensitive to mechanical disturbances. In all higher animals, sensory
reception is the special function of sensory neural elements, which
"translate" changes into nerve impulses. The biological significance of such a
feature is that it allows an organism to make appropriate reactions to changed
circumstances; without such provisions it would be in constant
danger of injury or death at the slightest environmental alteration. In
general, the more highly evolved the organism, the greater the number of
environmental changes sensed and the more precisely each is analyzed. Some
organisms, however, possess special senses developed for perceiving environmental
changes not registered by, nor relevant to, other species.

This article examines the various sensory capacities of living organisms,
explains the mechanisms of sensory function, and considers the adaptive
advantages of sensing. Human sensory reception is presented in a separate
section, followed by a detailed treatment of human vision and hearing.
Diseases and impairments of function of these latter two vital senses are
also discussed.

This abstract and review was obtained from OnLine subscription services -
courtesy of Charles Turley.