Demonstrate some fundamental physiological properties of the nerve impulse.

The aim of this experiment is to demonstrate some fundamental physiological properties of the nerve impulse. In this experiment, students stimulate and record extracellularly from the median and lateral giant axons of the common earthworm (Lumbricus spp.). Students will determine the threshold voltage of the median giant axon and the nerve refractory period of the median giant axon and lateral giant axons. Students can also observe whether or not the nerve is capable of producing an action potential in the opposite direction. This experiment is suitable for students with basic knowledge of the PowerLab Data Acquisition System and Scope Application.