Nerves

Types of neurone

• Sensory neurone

  • relays impulses from sensory receptors to the brain or spinal cord

• Motor neurone

  • Relays impulses from the brain or spinal cord to the muscles and organs

• Relay neurone

  • Transmits impulses between neurones

Neurone pathway

Receptors and effectors

• sensory neurones convert a stimulus from receptors into an electrical impulse

• passed along the sensory neurone to the brain or relay neurones

• the brain or relay neurones then pass the impulse onto a motor neurone which transmits the impulse to an effector

• effectors are usually muscles or glands which cause a response

Receptors as transducers

• sensory receptors will only detect one type of stimulus

  • specific

• they convert a stimulus into an electrical impulse

• different types of stimuli are all converted into one type of impulse

  • a generator potential

Myelinated and non-myelinated neurones

• non myelinated neurones are found in the brain and spinal cord in the grey matter

• most other neurones are covered in myelin sheath

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