synapse and response

• Simple arc- reflex arc

  1. Heat, stimulus
  2. Pain receptor stimulated
  3. Electrical impulses sent along the sensory neurone
  4. Electrical impulses passes along the relay neurone in the spinal cord and the message sent to the brain for interpretation.
  5. Then the electrical impulses sent along motor neurone towards effector.
  6. Effector contracts to remove hand from the fire
• What is a synapse?


  a junction between two neurons
• Synapse Structure?

  -presence of vesicles containing neurotransmitter molecules

  -synaptic gap

  -receptor proteins
• Importance of synapse?

  -ensure impulses travels in one direction only.

  -the neurotransmitters release from one side of the neurone (axon of a neurone) and the receptors protein are located on the dendrites of the next neurone.
• What happens in the synapse?

  1. Nerve impulses arrives at the synapse
  2. Chemical messenger is released into the synaptic gap
  3. Neurotransmitter binds with a receptor protein on the membrane of the post-synaptic neuron
• Structure of neurones

  A) dendrites

  B) nucleus

  C) cell body

  D) axon

  E) synapse

  
• Three types of neurones

  A) motor neuron

  B) interneuron

  C) sensory neuron