Classroom Questions

Questions for ‘Zap, zap, zap! Our bodies are electric’ 

a silhoutte of a person standing on a rocky perch against a purple clouded sky and a lightning strike

We think of electricity as a big arc of charge, like the dramatic sparks of lightning in a thunderstorm (but don't stand in one!). But far tinier zaps drive processes throughout the body. They literally keep us alive.

Anton Petrus/Moment/Getty Images Plus

By Science News Explores

To accompany ‘Zap, zap, zap! Our bodies are electric’  

SCIENCE

Before Reading:

  1. Two bar-shaped magnets, each with a positive end and a negative end, are set near to each another. Sketch a picture showing how two such magnets would orient themselves. Use (+) and (-) symbols to indicate their positively and negatively charged ends. Next, imagine the magnets have two positively charged ends, but one side, the (++) side, is much more positively charged than the other side (+). If two such magnets are brought near one another, they will orient themselves similarly to the (+) and (-) magnets. What does this tell us about the importance of relative electrical charge, rather than absolute charges, in the science of electricity?
  2. Sketch a picture to illustrate how a hydroelectric dam works to generate electricity. (If you aren’t sure how a dam works, watch this short video.) In physics, energy is described as either (a) kinetic, which is energy of motion or (b) potential, which is stored energy. What aspect of a hydroelectric dam can be considered potential energy? What aspect or part can be regarded as kinetic energy?

During Reading:

  1. On which organ is the sino-atrial (SA) node located? What does this node do for the body?
  2. Contrast the electrical charge of the inside of a pacemaker cell at rest to the outside.
  3. What are ions? Pacemaker cells open channels in their membranes, allowing ions to pass through, which triggers a heartbeat. Why do sodium ions rush from outside the cell to the inside, rather than vice versa?
  4. Describe the movement of potassium ions during the triggering of a heartbeat.
  5. Edward Lakatta explains that “two tiny clocks” set our heartbeat’s pace. The first “clock” involves sodium and potassium ions. What kind of ion does the second “clock” operate on?
  6. How can scars left by heart attacks lead to future heartbeat-pacing problems?
  7. What is a neuron? What is an axon? What role does an axon serve in a neuron?
  8. How is the charge difference between the inside and outside of an axon similar to that of a pacemaker cell?
  9. Give one example of a medical condition that doctors sometimes treat with deep-brain stimulation.
  10. List the three main types of bone cells.
  11. What does it mean to describe a material, such as a bone, as being piezoelectric?

After Reading:

  1. Which of the three main types of bone cells plays the most direct role in building new bone? Which type helps to break down bone? Consider how these two types of cells, with such different roles, work together to maintain bone health. Based on your reading, why is the “bone-munching” cell just as crucial for maintaining healthy bones as those cells that create new bone material?
  2. Refer to your answer to Question 2 in Before Reading. Identify one similarity between the processes involved in generating electricity via a hydroelectric dam and those that go into generating and propagating an action potential. Identify one difference.
  3. This story explains that scientists are attempting to apply their understanding of electricity’s role in bone to help maintain the skeletal health of future space travelers. Besides what is mentioned in this story, what is another potential application for such knowledge? Explain how electricity’s role in either bone or heart health might improve people’s lives.