What is a Synapse
The term synapse is derived from the ‘syn’ which means together and ‘haptein’ which means to clasp. Sir Charles Scott Sherrington came up with this term synapse. In the human body the synapse plays a very important part as it passes the chemical or electrical signal from one cell to another.
The synapse is the basic structure that helps in passing these chemical and electrical signals by the neuron to the some other cells. With the help of this synapse the neuron can perform its essential function of the passing the chemical and the electrical signals. Hence the synapse plays a very important part in the structure of our body and the nervous system.
There are two major types of synapse namely the chemical synapse and the electrical synapse. They are both specialized in their respective areas and they basically form an integral part of the central nervous system.
The chemical synapse helps in conducting signals between two neurons and also between the neurons and the glands and the muscles. The chemical synapses are engaged in the transmission of signals from the presynaptic neuron to the postsynaptic one. a special chemical by the name of neurotransmitter is released by the presynaptic neuron. This neurotransmitter is released by the nerve impulse that produces the calcium ions. They mix with the proteins found in the vesicle membranes and finally the neurotransmitter chemical is released through some intermediate processes. These complex processes take a very low amount of time and the activity takes as soon as the nerve impulse or the action potential reaches the cell. The neurotransmitter binds the receptors that are present in the postsynaptic cell. The region between the presynaptic cell and the postsynaptic ell is called the synaptic cleft where the neurotransmitter is made available. The receptors present on the postsynapnatic cell then bind the neurotransmitter and the thereby the signal is passed. The neurotransmitter need to be finally removed after this and be done a number of ways which also includes the thermal vibrations. The neurotransmitter can also be broken down or metabolized to make them inactive and cause its removal.
The electrical synapses are specialized in conducting the signals at a faster rate which is one of the biggest advantages of this synapse over the chemical synapses. Hence it is used in some of the special cases like the reflexes that are of the defensive nature. The gap junctions are present in case of the electrical synapses. They conduct the electrical signals from the presynaptic cells to the postsynaptic cell using the method of changes in the voltages of the cells. Another big advantage of the electrical synapses is that they can conduct the signals in both directions which is certainly not the case with the chemical synapses. Hence this bidirectional flow of signals is a unique feature of the electrical synapse. However it must be noted here that the bidirectional flow may be absent in some of the cases.