1: Describe the changes in the neuron membrane that occur throughout the course of an action potential.

Which of the following statements best describes saltatory conduction? a. It inhibits direct neurotransmitter release. b. It transmits the action potential at the nodes of Ranvier andthus speeds up impulses on myelinated axons. c. It increases neurotransmitter release at the presynapticmembrane. d. It decreases neurotransmitter uptake at chemically gatedpostsynaptic channels. e. It removes neurotransmitters from the synaptic cleft.

Visit this site (http://openstaxcollege.org/l/neurolab) to see a virtual neurophysiology lab, and to observe electrophysiological processes in the nervous system, where scientists directly measure the electrical signals produced by neurons. Often, the action potentials occur so rapidly that watching a screen to see them occur is not helpful. A speaker is powered by the signals recorded from a neuron and it pops each time the neuron fires an action potential. These action potentials are firing so fast that it sounds like static on the radio. Electrophysiologists can recognize the patterns within that static to understand what is happening. Why is the leech model used for measuring the electrical activity of neurons instead of using humans?

Which of the following voltages would most likely be measured during the relative refractory period? +30 mV 0 mV -45 mV -80 mv