Structures of a Neurone:

• Neurones are cells in the nervous system that transmit nerve impulses

Sensory neurone:

• Send nerve impulses from receptors to the brain and spinal cord

Relay neurone:

• Connects sensory neurone to motor neurone
• Transmit impulse between the brain and spinal cord

Motor neurone:

• Carry information from the spinal cord or brain to the effectors

Synapse and transmission of information:

• Electrical impulse reaches synaptic knob and approaches presynaptic membrane
• Triggers synaptic vesicle to move towards the presynaptic membrane
• The synaptic vesicle fuses with the presynaptic membrane
• Neurotransmitters (chemical substances) stored in synaptic vesicles are released across the synaptic cleft
• Neurotransmitters bind with specific protein receptors at the postsynaptic membrane
• Generates new electrical signals/impulses
• Impulses will move along postsynaptic neurone or effector

Synapse plays important roles in:

• Controlling and integrating nerve impulses that are transmitted by stimulated receptors.
• Allow nerve impulses to be transmitted only in one direction because:
  • Synaptic vesicles are only present at the synaptic terminal.
  • Receptors are only present at the postsynaptic membrane.