Julia has just started a weight-lifting program. As she lifts a dumbbell, her muscles contract
Describe and explain how muscle contraction works at the molecular level:
How do actin and myosin interact in a sarcomere to bring about muscle contraction?
What roles do ATP and calcium play?
Describe the longer-term effect of Julia's program. How will her muscles adapt over time to the change in workload?
******** Explain what happens to bones as a result of these weight-bearing exercises. Include an explanation of calcium and bone remodeling and how this relates to homeostasis.*********
As you may know, bone is a specialized connective tissue that is undergoing constant changes to respond to the body's needs.
Bone is constantly being remodeled depending on what is occurring in the body. For example, when you break a bone, such as the fibula or tibia, the bone needs to remodeled in order to fix the break. So the portion of the bone that is not needed will undergo resorption by osteoclasts and then reformed in the needed areas by osteoblasts, termed ossification. See the bone and bone remodeling papers attached.
Bone reformation will also occur when other stressors are at work as well, such as environmental. For example, people who break piles of bricks and boards with their hands will cause the bone structure of their hands to change and thicken (more ossification is occurring ...
Bone remodeling relating to homeostasis is clearly referenced and explained in the tutorial.