Structure and function of neurons

• The 3 types of neurons are the sensory neuron, relay neuron and the motor neuron
• Positions of neurons are on page 4 of biopsychology
• Neurons are made up of- Cell body, dendrites, Axon, myelin sheath, nodes of Ranvier and terminal buttons
• Cell body- This includes the nucleus, which contains the genetic material of the cell
• Dendrites- These are branch like structures that carry nerve impulses from neighboring neurons to the cell body
• Axon- This carries the impulses away from the cell body down to the length of a neuron.
• Myelin sheath- This is a fatty layer that protects the axon and speeds up the electrical impulse
• Nodes of Ranvier- The myelin sheath is segmented by gaps to speed up the transmission of the impulse by forcing it to jump across the gaps along the axon.
• Terminal buttons- These communicate with the next neuron in the chain across the gap known as the synapse.
• Sensory neuron-

  The function of the sensory neuron is that it carries messages messages from the PNS to the brain and the spinal chord. They have long dendrites and shorts axons.
• Relay Neuron-

  The relay neuron transfers messengers from sensory neurons to other interconnecting neuron or motor neurons. They have short dendrites and short or long axons.
• Motor neuron- Carries messages from the CNS to effectors such as muscle and glands. They have short dendrites and long axons.