Sensory Receptors and Pathways

Sensory Receptors: Introduction

• Sensory receptors transduce (exchange) different forms of energy into nerve impulses.

  • Receptors behave similarly to dendrites.

• Stimuli produce depolarizations called generator potentials, which are similar to EPSPs (Excitatory Postsynaptic Potentials) and are graded.

• When the threshold is met, an Action Potential (AP) occurs.

• After threshold, a larger generator potential leads to a higher frequency of APs.

• Law of specific nerve energy: Information from a given nerve fiber can only be experienced as one stimulus type.

  • If a signal travels in the optic pathway, it will be perceived as light.

  • If a signal travels through the hearing pathway, it will be perceived as sound.

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