Focus Figure 11.11 - Action Potential - Neurophysiology Activities

Helpfulness: +1
Set Details Share
Page to share:
Embed this setcancel
code changes based on your size selection

Interpreting an Action Potential Tracing.

Using the tracing above, drag each of the terms or values on the left to correctly complete the sentences on the right.

  • 1. This neuron is most depolarized at (+30) mV.
  • 2. This neuron spends approximately (2.5) msec in a hyperpolarized state.
  • 3. The ion (K+) is crossing the cell's plasma membrane at 1.5 msec.
  • 4. This cell reaches threshold at approximately (0.6) msec.

What does 0 mV on the Y-axis of an action potential tracing represent?

The cell's membrane is at equilibrium.

card image

Comparing and contrasting the two types of voltage-gated ion channels


- The stimulus that triggers opening

- The polarity of the substances they transport across the membrane

- The placement of channel protein relative to the membrane


Comparing and contrasting the two types of voltage-gated ion channels


- The direction of ion movement through the channel

- The inactivation mechanism


Comparing and contrasting the two types of voltage-gated ion channels

- Both channels have inactivation gates

- They move Na+ and K+ in the same direction

card image

Understanding the sequence of action potential events

An important aspect of learning physiology is understanding the cause-and-effect relationships in pathways. This activity will test your understanding of the sequence of events in an action potential. Place the action potential events below in the correct sequence. If two events occur simultaneously, place one on top of the other.

1. Activation gates on NA+ channels open; Na+ enters cell.

2. Cell Depolarizes.

3. Inactivation gates on Na+ channels close
Activation gates on K+ channels open; K+ leaves cell

4. Cell Repolarizes.

5. Activation gates on K+ channels begin to close

6. Cell experiences hyperpolarization.

card image

Matching ion channel states with the phases of the action potential

Match each phase of an action potential with the states of the ion channels you have studied. Drag the labels onto the table to indicate whether the channel is open, closed, or inactivated at the given phase of an action potential. You may use a label once or more than once.

Resting State: Na+ channels closed, K+ channels closed

Depolarization: Na+ open, K+ closed

Repolarization: Na+ inactivated, K+ open

Hyperpolarization: Na+ closed, K+ open


Understanding why hyperpolarization happens

Following repolarization, the neuron may become slightly hyperpolarized before it re-establishes its resting membrane potential.

Hyperpolarization is due to a difference between how the voltage-gated Na+ and K+ channels work. What is this difference?

Voltage-gated Na+ channels stop the flow of Na+ relatively quickly, while voltage-gated K+ channels are slow to close, resulting in the overshoot.


Making predictions based on your understanding

Interpreting tracings of membrane potential is an important skill in a course like this. In future chapters, you will see other instances of cells experiencing changes in membrane potential. For example, the tracing below is from a cardiac muscle fiber that is undergoing an action potential.

Based on your knowledge of action potentials in neurons, what can you conclude about how they occur in cardiac muscle fibers?

Cardiac muscle fibers depolarize more quickly and spend more time depolarized than neurons do.

Related pages

functions of tricuspid valvehow many cells in mitosisaltruistisepicardium myocardiumtheory of how evolution occursthe board of governors of the federal reserve system determinestundra amount of rainfallplasma membrane bilayersteppe landformshape of nh3intersexual selection vs intrasexual selectionopioids relieve pain by blocking the release ofwhat is homeostasis kid definitionfrench revolution apushthe male gonads are thepathway of spermthe person centered therapist is best described as aabdominal girdle musclescoccyx varafunction of pericardial cavityautonomic dysreflexia is characterized bymedical terminology chapter 2 testerythrocyte developmentchapter 6 the muscular system answer keysemiconservative model of dnarole of atp in muscle contraction and relaxation6co2 6h2o atpwhich of the following statements about allopolyploid individuals is truechapter 6 cell energy photosynthesis and respirationelementary statistics triolain the epiphyseal plate cartilage growscephalic phase of gastric secretiongreatest biodiversity on earthcampbell biology 8thhemal systemabiotic factors in taigawhere is glycogen stored in the cellwhat is sister chromatidsintrinsic rate of increase definitionreactant biologyprotist examplewhere does cellular respiration begin and endecori restriction siteextracellular fluid electrolyteswhich substance is needed to begin the process of glycolysishow does the genetic code get to a ribosomeequilibrium ear balancebacillus classificationepicranial aponeurosiswhich number represents the mature gametophytewhat is the function of the ureterenlargement of the spleen is termedhow many molecules of oxygen can hemoglobin carrycyst and trophozoitememorize the 20 amino acidsexample of sporophytesize of hemoglobin moleculethe space between the neuron and the muscle is thebasophil nucleus shapehow to find confidence interval for population meanwhich of the following is not a jovian planetleft lateral decubitus abdomenrespiratory system anatomy quizthe digestive function of the liver is to produce bilewhat bacteria are selected for when using macconkey agarcarbohydrate metabolism questionsnaming bases and acidsoutline the composition of bonethe phylogenetic distribution of the enzyme rubisco is limited tobartending 101 basic drinkspicogramswhat occurs during the latent period of muscle contraction