Question

What is a synapse? In a neuron cell, how is an electrical impulse created and what is the role of synapse in this context?

Answer 1

We all know that neuron is the basic structural and functional unit of the neural system. They are highly specialized cells and perform basic functions of coordination and control. The impulse generated by certain stimuli travels through neurons and helps to perform various activities by the body.

Complete answer: The junction between two neurons is called a synapse. Keep in mind that we also call a junction between a neuron and a muscle by the same name. Synapse is formed by the members of the presynaptic neurons and postsynaptic neurons. They are separated by a gap called the synaptic cleft. Remember that in some cases synapse is not seen.
we can see two types of synapse in humans. They are electrical and chemical synapses. Impulse transmission from one neuron to another takes place when the neurotransmitter is released from the presynaptic neurons to the synaptic cleft. keep in mind that in electrical synapses both membranes are so close that neurotransmitter is not needed for the impulse transmission. It is only seen in chemical synapses.
In the presynaptic neuron. the axon terminals contain several vesicles that are filled with neurotransmitters. When an impulse reaches the presynaptic neuron, neurotransmitters are secreted to the synaptic cleft. They bind to the receptors present in the postsynaptic membrane, and the impulse is transmitted to the postsynaptic neuron.
Acetylcholine and dopamine are the two important neurotransmitters present in the human body. Certain other chemicals can also act as neurotransmitters.

Note: Norepinephrine which is a member of catecholamines acts as neurotransmitters in our body. They are also called noradrenaline. It is actually a stress hormone released by the adrenal gland. They are secreted in stress conditions and help the body to manage it.