How a Response is Generated by Effectors (Edexcel IAL Biology)

Spec point — 8.2

How a Response is Generated by Effectors

• The nervous system enables the body to detect changes in the environment and brings about appropriate responses to ensure its safety

  • Receptor cells detect changes in the environment, or stimuli

  • Nerve impulses travel from the receptor cells along sensory neurones to the central nervous system, or CNS

  • The **CNS **acts as a coordinating centre for the impulses that arrive from the receptors, determining which part of the body needs to respond and sending out a new set of impulses along motor neurones

  • Motor neurones send impulses to the** effectors** to bring about a response

    • Effectors may be muscles or glands

• Nerve impulses pass through the nervous system along the following pathway

stimulus$\rightarrow$receptor$\rightarrow$sensory neurone$\rightarrow$CNS$\rightarrow$motor neurone$\rightarrow$effector

Receptors detect stimuli and impulses are sent through to the nervous system to bring about a response in the effector