Print Options

Card layout: ?

← Back to notecard set|Easy Notecards home page

Instructions for Side by Side Printing
  1. Print the notecards
  2. Fold each page in half along the solid vertical line
  3. Cut out the notecards by cutting along each horizontal dotted line
  4. Optional: Glue, tape or staple the ends of each notecard together
  1. Verify Front of pages is selected for Viewing and print the front of the notecards
  2. Select Back of pages for Viewing and print the back of the notecards
    NOTE: Since the back of the pages are printed in reverse order (last page is printed first), keep the pages in the same order as they were after Step 1. Also, be sure to feed the pages in the same direction as you did in Step 1.
  3. Cut out the notecards by cutting along each horizontal and vertical dotted line
To print: Ctrl+PPrint as a list

17 notecards = 5 pages (4 cards per page)

Viewing:

Exercise 18B: Neurophysiology of Nerve Impulses - Computer Simulation

front 1

Why don’t the terms depolarization and action potential mean the same thing?

back 1

A depolarization is any change in a neuron that makes it more positive than resting potential, but an action potential only occurs when the depolarization reaches the threshold level.

front 2

What was the threshold voltage in Activity 1?

back 2

3.0 V

front 3

What was the effect of increasing the voltage? How does this change correlate to changes in the nerve?

back 3

Increasing voltage results in depolarization of increasing numbers of neurons in a nerve.

front 4

How did the action potential generated with the unheated rod compare to that generated with the heated rod?

back 4

The action potential generated with the unheated rod was less than the action potential generated by the heated rod.

front 5

Describe the types of stimuli that generated an action potential.

back 5

Electrical, mechanical, thermal, and chemical stimuli are all capable of generating an action potential.

front 6

If you were to spend a lot of time studying nerve physiology in the laboratory, what type of stimulus would you use and why?

back 6

Although many different stimuli work, electrical stimulators are convenient because the voltage duration and frequency of the shock can be very precisely set for use.

front 7

Why does the addition of sodium chloride elicit an action potential? Hint: Think about the sodium permeability of the neuron (Figure 3.2e).

back 7

While the sodium-potassium pump is pumping sodium out of the cell and potassium into the cell, these ions are leaking back where they came from by diffusion. By adding sodium chloride, a more-than-normal amount of sodium will diffuse into the nerve, causing the resting membrane potential to reach the threshold value, bringing about a membrane depolarization.

front 8

What was the effect of ether on eliciting an action potential?

back 8

There was no effect it conducted the same

front 9

Does the addition of ether to the nerve cause any permanent alteration in neural response?

back 9

No, the ether has no lasting effect.

front 10

Ok, so you’re using my notecards which is great. I am glad I could help you out cause I wish I had someone to help me out when I took this course. I know Anatomy is super hard.

back 10

I only ask that if you find these notecards helpful, you join Easy Notecards and create at least one notecard set to help others out. It can be for any subject or class. Thanks and don’t forget to rate my helpfulness!

front 11

What was the effect of curare on eliciting an action potential?

back 11

Curare had no effect - an action potential

front 12

Explain the reason for your answer to question 10 above.

back 12

Curare stops Acetylcholine. It creates a depolarisation block. Disinhibition from blocking interneurons that express nicotinic accetylcholine receptors.

front 13

What was the effect of lidocaine on eliciting an action potential?

back 13

Lidocaine is an antagonist inhibitor that blocks sodium ion channels, when these are blocked there's no action potential (nerve impulses).

front 14

What is the relationship between size of the nerve and conduction velocity?

back 14

A larger nerve will have a faster conduction velocity.

front 15

Keeping your answer to question 13 in mind, how might you draw an analogy between the nerves in the human body and electrical wires?

back 15

Larger electrical wire has less resistance to current flow and will conduct faster than smaller wire with increased resistance to current flow.

front 16

How does myelination affect nerve conduction velocity? Explain, using your data from Chart 1.

back 16

Myelination speeds up nerve conduction velocity by causing the nerve impulse to jump across the cell membrane from one internode to another rather than be conducted across the entire cell membrane.

front 17

If any of the nerves used were reversed in their placement on the stimulating and recording electrodes, would any differences be seen in conduction velocity? Explain.

back 17

No. Once a neural membrane is depolarized and the impulse is being conducted along the neural membrane, which direction is which does not matter. We state that a neural impulse is set up in the neuron’s trigger zone (mainly due to the large number of sodium channels there) but once the depolarization is set up, it not only travels down the axon but also around the soma of the cell.