Adequate stimulus
Encyclopedia
The adequate stimulus is a property of a sensory receptor
that determines the type of energy to which a sensory receptor responds to with the initiation of sensory transduction.
A sensory receptor's adequate stimulus is determined by the signal transduction mechanisms and ion channels incorporated in the sensory receptor's plasma membrane.
Although Muller proposed in his doctrine that any stimulus to a sensory receptor will invoke the same perception, we have now built on that theory by adding that an adequate stimulus is a type of stimulus for which a given sensory organ is particularly adapted towards.
Sensory receptor
In a sensory system, a sensory receptor is a sensory nerve ending that responds to a stimulus in the internal or external environment of an organism...
that determines the type of energy to which a sensory receptor responds to with the initiation of sensory transduction.
A sensory receptor's adequate stimulus is determined by the signal transduction mechanisms and ion channels incorporated in the sensory receptor's plasma membrane.
Classes
- Light – When the adequate stimulus of a sensory receptor is light, the sensory receptors contain pigment molecules whose shape is transformed by light. Changes in these molecules activate ion channels which initiate sensory transduction.
- Sound – When the adequate stimulus of a sensory receptor is sound, the sensory receptors are hair cellHair cellHair cells are the sensory receptors of both the auditory system and the vestibular system in all vertebrates. In mammals, the auditory hair cells are located within the organ of Corti on a thin basilar membrane in the cochlea of the inner ear...
s (mechanoreceptorMechanoreceptorA mechanoreceptor is a sensory receptor that responds to mechanical pressure or distortion. There are four main types in the glabrous skin of humans: Pacinian corpuscles, Meissner's corpuscles, Merkel's discs, and Ruffini corpuscles...
s). These hair cells contain stereociliaStereociliaIn the inner ear, stereocilia are the mechanosensing organelles of hair cells, which respond to fluid motion in numerous types of animals for various functions, including hearing and balance. They are about 10–50 micrometers in length and share some similar features of microvilli...
, which when bent, trigger the opening of ion channels. Thus hair cells transform the pressure waves of the sound into receptor potentials to initiate sensory transduction.
Although Muller proposed in his doctrine that any stimulus to a sensory receptor will invoke the same perception, we have now built on that theory by adding that an adequate stimulus is a type of stimulus for which a given sensory organ is particularly adapted towards.