PSYC 2330 Lecture Notes - Lecture 4: Reflex Arc, Efferent Nerve Fiber, Afferent Nerve Fiber

• School: University of Guelph
• Department: Psychology
• Course: PSYC 2330
• Professor: Jennifer Murray

Document Summary

In all species, what and how learning takes place depends on the preexisting behavioural organization of the organism. A reflex involves two closely related events: an eliciting stimulus and a corresponding response. Furthermore, the stimulus and the response are linked. Presentation of the stimulus is followed by the response, and the response rarely occurs in the absence of the stimulus. In vertebrates, simple reflexes are typically mediated by three neurons. The environmental stimulus for a reflex activates a sensory neuron (afferent neuron), which transmits the sensory message to the spinal cord. The messages are then relayed though at least one interneuron and then to the motor neuron (efferent neuron), which activates the muscles involved in the reflex response. A particular reflex response is elicited only by a restricted set of stimuli. The afferent neuron, interneuron, and efferent neuron together constitute the reflex arc. The reflex arc in vertebrates represents the fewest neural connections necessary for reflex action.