Final answer:
Five ways force is increased in electrically stimulated contractions are recruitment of more muscle fibers, increasing the frequency of action potentials, optimizing the length-tension relationship, increasing calcium concentration, and releasing more neurotransmitters.
Step-by-step explanation:
Electrically stimulated contractions can increase force in several ways.
- Recruitment of more muscle fibers: When more muscle fibers are activated, the force of contraction increases. This can be achieved by increasing the intensity of electrical stimulation.
- Increasing the frequency of action potentials: When action potentials are fired rapidly, the force of contraction is increased.
- Length-tension relationship: The force of contraction is greatest when the muscle is at an optimal length. Applying electrical stimulation at this length can increase force.
- Increasing calcium concentration: Calcium is required for muscle contraction. By increasing the concentration of calcium in the muscle, the force of contraction can be increased.
- Releasing more neurotransmitters: Electrical stimulation can lead to the release of more neurotransmitters, which can enhance the force of contraction.