Neurons and synaptic transmission

-Nerve cells that process and transmit messages through electrical and chemical signals

-Motor Neuron -Relay Neuron -Sensory neuron

-They connect the CNS to the effectors (muscles and glands) -Long axons -Short dendrites -soma (cell body) with nucleus -Begin in the CNS but their long axons form part of PNS

-They connect the sensory neurons to the motor or other relay neurons -Short dendrites -Short axons -soma (cell body) with nucleus -Make up 97% of all neurons

-They carry messages from the PNS to the CNS. -Long dendrites -Short axons -soma (cell body) with nucleus -Found in clusters (ganglia) in the PNS

-They carry impulses down the length of the cell body of the neuron

-Branchlike structures that protrude from the cell body which carry impulses from neighbouring neurons towards the cell body

• A fatty layer which covers the axon, protecting it and speeding up rate of electrical transmission of impulse

-These are gaps in the myelin sheath which speed up the rate of transmission of electrical impulses as they have to jump across the gaps.

-Knobs at the end of an axon that communicate with the next neuron in the chain across the gap known as a synapse.

-The process by which neighbouring neurons communicate with eachother by sending chemical messages across the synapse (the gap) that separates them -This process is one-way (pre-synaptic release the neurotransmitter and post-synaptic receives it) -When it reaches the Post-synaptic site it is turned back into a electrical impulse

-Chemicals that are released from synaptic vesicles that relay signals across synapses to other neurons -Neurotransmitters are either excitaory or inhibitory -Examples = Serotonin (mood regulation) + acetylcholine(ACh) which cause muscle contraction.

-When a neurotransmitter increases the positive charge of the postsynaptic neuron. -This increases the likelihood that the neuron will fire and pass on the electrical impulse. -Adrenaline is a excitaory neurotransmitter

-When a neurotransmitter makes the charge of the postsynaptic neuron more negative. -This decreases the likelihood that the neuron will fire and pass on the electrical impulse. - Serotonin is an inhibitory neurotransmitter.

-the sum of the overall inhibitory and excitaory influences -if the net effect is inhibitory- neuron is less likely to be fired -if net is excitaory it is more likely to be fired

-a neural impulse a brief electrical charge that travels down an axon -This is when the inside of the cell changes from negatively charged to positively charged because a stimulus causing the firing of a electrical impulse.