Neurones and Synapse

 
12.3 Neurones and Synapse
 

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.
 

 

Neurones and Synapse

 
12.3 Neurones and Synapse
 

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.