Muscle contraction is initiated by a signal sent by the central nervous system by the release of . . . . . . .

Assertion : Transmission of nerve impulse across a synapse is accomplished by neurotransmitters.
Reason : Transmission across a synapse usually requires neurotransmitters because there is a small space, i.e., $synaptic \ cleft$, that separates one neuron from another.

Explain the process of transport and release of neurotransmitter with the help of a labelled diagram,showing complete neuron,axon terminal and synapse.

After the transmission of one impulse from the synapse,it cannot transmit another impulse immediately because one of the following chemicals is active there:

Select the incorrect statement regarding synapses :

Synapses store