Which of the following occurs during a muscle contraction ?
| | The distance between the z-discs lengthens |
| | The A band shortens |
| | The I band and the A band switch positions |
| | thick and thin myofillaments shorten |
| | The sarcomeres shorten |
Jogging, swimming, and aerobics all have this effect on skeletalmuscle tissue.
| | Decreased # of myofillaments |
| | Increased # of nuclei per muscle cell |
| | Increased # of motor units |
| | None of the above |
| | Increased # of muscle fibers |
In the sliding filament model, ________ stay in place and________ are pulled toward the center of the
sarcomere.                                                                          Â
| | Z bands, A bands
|
| | thin filaments, thick filaments |
| | muscle cells, myofibrils |
| | fast fibers, slow fibers |
| | myosin filaments, actin filaments |
