Which of the following provides the final 'go signal' for muscle contraction?

When Eric returned from jogging, he was breathing heavily and sweating profusely, and he complained that his legs ached and felt weak. On the basis of what you have learned about muscle energy metabolism, respond to the following questions:

b. What ATP-harvesting pathway have his working muscles been using that leads to such a breathing pattern?

When Eric returned from jogging, he was breathing heavily and sweating profusely, and he complained that his legs ached and felt weak. On the basis of what you have learned about muscle energy metabolism, respond to the following questions: c. What metabolic product(s) might account for his sore muscles and his feeling of muscle weakness?

Smooth muscle has some unique properties, such as low energy usage, and the ability to maintain contraction over long periods. Tie these properties to the function of smooth muscle in the body.