The transport of impulses across synapses is called synaptic transmission. It takes 7 milliseconds for an impulse to flow through a neuron. Its speed is faster than the speed of light. The process of impulse transport is-
1. As the nerve impulse reaches the synaptic knob of the presynaptic neuron, its permeability increases.
2. As a result, Ca++ ions from the surroundings enter the synaptic knob. Ca++ ion converts ATP-as enzyme into active enzyme.
3. The activated enzyme releases the neurotransmitter.
4. Neurotransmitters pass through the synaptic cleft to the receptors of the postsynaptic neuron in the diffusion process.
5. This increases the permeability of the synaptic knob of the postsynaptic neuron. As a result, Na+ ions enter the synaptic knob and K+ ions move out.
6. An action potential is generated by the exchange of Na+ and K+. A signal is generated as a result. Through this signal, the stimulus is carried to the postsynaptic neuron.