6-2-1-motor-neurone-structure

Myelinated motor neurones

• Information is transmitted through the nervous system as nerve impulses; electrical signals that pass along neurones

  • A bundle of neurones is known as a nerve

• Different types of neurone carry nerve impulses in different parts of the nervous system:

  • Sensory neurones carry impulses from receptors to the CNS

  • Relay neurones connect sensory and motor neurones within the CNS

  • Motor neurones carry impulses from the CNS to effectors

• While each type of neurone differs slightly in structure, motor neurones can be identified by the presence of the following features:

  • a cell body at one end, within the CNS

  • a long axon

  • axon terminal endings, located within effectors

• Some motor neurones also have a myelin sheath; these cells are said to be myelinated

  • Myelin is a fatty substance made by Schwann cells which wrap themselves around the axon

  • The presence of myelin speeds up the conduction of nerve impulses