neurons and synaptic transmissions

neurons and synaptic transmissions

1. the central nervous system (CNS)

   • brain = conscious awareness
   • spinal cord = passes messages to and from the brain
     • connects nerves to PNS
     • responsible for relax action

2. The Peripheral nervous system

   • transmits messages through millions of neutrons to CNS
   • Autonomic nervous system
     • breathing
     • heart rate
     • digestion
     • stress responses
   • somatic nervous system
     • muscle movement

3. neurons

   • sensory neuron
     • carry messages from PNS to CNS
     • long dendrites and short axon
   • relay neuron
     • connect sensory to motor
     • short dendrites and short axon
   • motor neurons
     • short dendrites and long axons
     • connect CNS to effectors ie. muscle and glands

4. synaptic transmission

   • Action potential travels down presynaptic synapse
     • when electrical pulse reaches end of neuron
       • electrical impulse goes into vesicles
         • this the triggers the release of neurotransmissions
           • these diffuse across the the synapse to the postsynaptic synapse
             • to the postsynaptic receptor site
               • if positive charge (excitation) action potential more likely ie. adrenaline
               • if negative charge less like to fire action potential (inhibition) ie. serotonin
               • summation
                 • the sum if going to be more excitation or inhibition
             • diffuse chemically

5. The structure of a neuron

   • axon= carries impulse away from cell body
   • nodes of ranvier = gaps to action potential jumps
   • myelin sheath= protects axon and speeds up electrical transmission
   • cell body = includes nucleus (Store genetic info)
   • direction of conduction= one way