Hint:The conduction of nerve impulse is the process of transfer of a message along a neuron in the form of an electrical signal. This process is fastened by saltatory conduction. Myelin sheath helps in saltatory conduction.
There are three basic stages of conduction of nerve impulse. They are –
1. Excitation-contraction coupling
2. Tension generation
The latent period is the time lag between the application or reception of the stimulus and the onset of contraction. Here, excitation-contraction coupling also takes place.
The contraction time is the time between the onset of contraction and peak tension.
The relaxation time is the time between peak tension and the point when tension returns to the baseline.
So, the correct answer is the option B, Contraction time.
Conduction of nerve impulse occurs because of the presence of active electronic potentials along the conductors. Transmission of these signals internally between the cells is achieved through a synapse. Nerve conductors have relatively higher membrane resistance and low axial resistance. The electrical synapse has a role in escape reflexes, heart, and in the retina of vertebrates. They are used whenever there is a requirement for a quick response and where timing is very crucial. The ionic currents pass through the two nerve cell membranes when the action potential reaches the stage of a synapse.
Note: The conduction of nerve impulse is a very fast process. This lightning-fast speed is achieved due to the presence of a myelin sheath. This process is termed saltatory conduction.