The basic pathway for a nerve impulse is described by the stimulus response model
- A stimulus is a change in the environment (either external or internal) that is detected by a receptor
- Receptors transform environmental stimuli into electrical nerve impulses
- These impulses are then transmitted via neurons to the central nervous system where decision-making occurs
- When a response is selected (consciously or unconsciously), the signal is transmitted via neurons to effectors
- Effectors are organs (either muscles or glands) that produce a response to a stimulus
- A response is a change in the organism resulting from the detection of a stimulus
Overview of the Stimulus-Response Pathway
Three types of neurons are required to transmit information via the stimulus-response pathway:
- Sensory neurons transmit information from sensory receptors to the central nervous system (CNS)
- Relay neurons (interneurons) transmit information within the CNS as part of the decision-making process
- Motor neurons transmit information from the CNS to effectors (muscles or glands), in order to initiate a response
While these three types of neurons share common features, their basic structure may differ slightly according to their function
- This includes their length, cell body (soma) position and the comparative distribution of dendrites and axon terminals
Types of Nerve Cells
