Neurophysiology of nerve impluses review sheet exercise 3

What reason can you give for your answer? This active transport mechanism moves 3 sodium ions out of the cell while moving in 2 potassium ions.

This is easily registered and viewable on an oscilloscope, without the aid of an amplifier. This will narcotize the worm so it does not move around during the experiment, but will not affect nerve conduction velocity. On the left side of the screen are the four nerves which will be studied.

Click on the glass rod and drag it to the heater, releasing the mouse button. Click and drag the dropper from the bottle marked Curare and position the dropper on the nerve, in between the stimulating and recording electrodes. Increase the voltage by 0.

The action potential you will see on the oscilloscope screen reflects the cumulative action potentials of all the neurons in the nerve, called a compound nerve action potential. Explain, using your data from Chart 1.

When you electrically stimulate a nerve at a given voltage, the stimulus may result in the depolarization of most of the neurons, but not necessarily all of them.

To begin, select Neurophysiology of Nerve Impulses from the main menu. When a neuron is activated by a stimulus of adequate intensity, known as a threshold stimulus, the membrane at its trigger zone, typically the axon hillock, briefly becomes more permeable to sodium ions sodium gates in the cell membrane open.

Click the Clear button on the oscilloscope. Does this generate an action potential? This will return the nerve to its original non-salted state.

The change which occurs here during depolarization will be so miniscule that it must be amplified in order to be visible on the oscilloscope. The nerves included are the earthworm, a frog nerve, and two rat nerves of different sizes. Lidocaine is a sodium-channel antagonist. Release the mouse button to dispense drops.

How does this change correlate to changes in the nerve?

Sodium ions rush into the cell, increasing the number of positive ions inside of the cell and changing the membrane polarity. To list at least two agents capable of inhibiting an action potential.

A frog nerve is used as the frog has long been the animal of choice in many physiology laboratories. This amount of time, usually in milliseconds, is critical for determining conduction velocity.

Watch the Elapsed Time display.


The inner surface of the cell membrane is more negative than the outer surface, mainly due to intracellular proteins, which, at body ph, tend to be negatively charged.

Two electrodes will be used to bring the impulse from the stimulator to the nerve and three will be used for recording the membrane depolarization. Electronic circuitry allows for the electron beam to be brought across the screen in pre-set time intervals.

To list at least four different stimuli capable of generating an action potential. Click Clear to clear the oscilloscope for the next activity. Click and drag the earthworm into the nerve chamber.

While performing the following experiments, keep in mind that you are working with a nerve, which consists of many neurons-- you are not just working with a single neuron. Remember, the red wire is the hot wire that carries the impulse from the stimulator and the black wire is the return to the stimulator that completes the circuit.

What is the major reason for the differences seen in conduction velocity between the myelinated nerves and the unmyelinated nerves? If not, increase the voltage by increments of 1. The wiring of the circuit may seem complicated, but really is not.

The beam passes to the front of the tube. To continue on to the next activity, click the Experiment pull-down menu and select Inhibiting a Nerve Impulse. Think about the sodium permeability of the neuron Figure 3. When 2 depolarization reaches a certain called threshold, an action potential is initiated and the polarity of the membrane reverses.Review Sheet Exercise 3 Neurophysiology of Nerve Impulses NAME LAB DATE/TIME Eliciting (Generating) a Nerve Impulse 1.

Why don’t the terms depolarization and action potential mean the same thing? Because depolarization is the shift in electrical potential across a plasma membrane toward 0 to mV and action potential is a rapid voltage. I am looking for answers to the Review Sheet portion of Exercise 3: Neurophysiology of Nerve the lab book these questions start on page PEx and end on page Pex The first question: Q:Explain why increasing extracellular k+ reduces the net diffusion of k+ out of the neuron through the k+ leak channels.

REVIEW SHEET EXERCISE 3 Neurophysiology of Nerve Impulses Name Lab Time/Date. The Resting Membrane Potential REVIEW SHEET EXERCISE 3 Neurophysiology of Nerve Impulses Name Lab Time/Date ACTIVITY 1 The Resting Membrane Potential 1.

Start studying physioEx Exercise 3: Neurophysiology of nerve impulses. Learn vocabulary, terms, and more with flashcards, games, and other study tools. Solved by ramonistry Exercise 3: Neurophysiology of Nerve Impulses: Activity 1: The Resting Membrane Potential Lab [PhysioEX Chapter 3 exercise 1] PEX ramonistry (25) in physioex Review Sheet Results.

View Neurophysiology of Nerve Impulses from PHGY at University of South Dakota. PhysioEx Exercise 3: Neurophysiology of Nerve Impulses Name: ALEXA DILLON Activity 1: The Resting Membrane.

Neurophysiology of nerve impluses review sheet exercise 3
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