Synape and nervous system

Synapse
A synapse is a structure that permits a neuron to pass an electrical or chemical signal to another cell (neural or otherwise). Synapses are essential to neuronalfunction: neurons are cells that are specialized to pass signals to individual target cells, and synapses are the means by which they do so. At a synapse, the plasma membraneof the signal-passing neuron comes into close apposition with the membrane of the target cell. Both the presynaptic and postsynaptic sites contain extensive arrays ofmolecular machinery that link the two membranes together and carry out the signaling process.

Central and Peripheral nervous system
Central nervous system (CNS): The centralnervous system is that part of the nervous system that consists of the brain and spinal cord. Is one of the two major divisions of the nervous system. The other is theperipheral nervous system (PNS) which is outside the brain and spinal cord.
The central nervous system is involved in voluntary actions, such as talking and sends the nerveimpulse through neurons, to the brain.

Peripheral nervous system (PNS): The peripheral nervous system (PNS) connects the central nervous system (CNS) to sensory organs(such as the eye and ear), other organs of the body, muscles, blood vessels and glands. The peripheral nerves include the 12 cranial nerves, the spinal nerves and roots, andwhat are called the autonomic nerves that are concerned specifically with the regulation of the heart muscle, the muscles in blood vessel walls, and glands.
The peripheralnervous system is involved in reflex actions, such as blinking or breathing and sends the nerve impulse through a relay neurone to the spine and spinal cord, not to the brain.