Signal Transmission at Synapses
The transmission of nerve signals across synapses allows for information to be integration between the central and peripheral nervous systems and the rest of the body.
Presynaptic neuron : neuron that sends an impulse
Postsynaptic neuron : neuron that receives an impulse
Most synapses are:
Axodendritic – Axon of one neuron to dendrite of another
Axosomatic – Axon of one neuron to cell body of another
Axoaxonic – Axon of one neuron to axon of another
Types of Synapses
Electrical Synapses
At electrical synapses, action potentials are conducted between adjacent cells via gap junctions and can be transmitted in both directions.
e.g. visceral smooth muscle, cardiac muscle, developing embryo, and CNS neurons
Advantages:
a) Faster communication: signal is delivered directly from presynaptic to postsynaptic cell b) Synchronization: a large number of neurons can produce action potentials in unison to allow a coordinated contraction. This is due to numerous gap junctions.
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