Describe changes in human muscle contractile character with increasing age.

How much of our muscle mass do we lose by the time we are 70?

Explain the reason for reduced activation of muscles as we age?

Describe the process of collateral innovation and why this might results in muscle fiber types being arranged in a mosaic pattern.

Does activity stop the process of aging? explain

Describe how motor units are remodeled during aging.

What happens to the fiber twitch when we change one fiber type.

Describe what happens to the sarcoplasmic reticulum efficiency as we age. How can this affect our muscle endurance?