Explain on a separate sheet why the second threshold stimulus current is different from the first. Devise an experiment to determine the absolute refractory period of the axon. Describe how you may determine the relative refractory period of the axon. The long processes of most vertebrate neurons are myelinated. Myelin is the white matter of the central nervous system, and of peripheral nerves e.g. the sciatic.
Impulses form only at the nodes - and propagate by jumping from one node to the next.
But if the nodes are too far apart, impulse conduction fails. Type enter until you see the jumping impulse. Develop and perform an experiment, and record your results, which measures the maximum spacing of the nodes for the impulse to just propagate. Then, keeping this maximum spacing, reduce the axon diameter. Voltage Clamp First run the demonstation at slow speed and explain the Na and K conductance changes.