neurons and synaptic transmission

• neurons have cell body/nucleus, dendrites, axons, terminal buttons , nodes of Ranvier, myelin sheath
• cell body contains genetic material, dendrites connect to other neuron, axon carries impulses down to dendrites, myelin sheath protects axon, nodes of Ranvier causes impulse jump speeding up transmission of impulse, terminal button connect dendrites across synapse to neuron
• electrical transmission is when neuron is resting at a negative charge ,stimulus causes it to become positively charged causing action potential, creating electrical impulse
• signals within neuron are transmitted electrically but between neurons signals are transmitted chemically
• when electrical impulse reaches end of neuron, neurotransmitters are released from vesicles
• neurotransmitters diffuse the chemical signal across synapse to post synaptic receptor site which converts it back to electrical impulse
• neurotransmitters has specific molecular structure complimentary for psot synaptic site
• neurotransmitter has excitatory or inhibitory effect
• inhibitory effect makes inside of cell more negative so it is less likely to fire e.g. serotonin. excitatory effect increases positive charge making it more likely to fire e.g. adrenaline
• sum of excitatory or inhibitory signals need to reach threshold in order for action potential to occur and electrical impulse this is called summation