Final answer:
Hormones play a role in regulating the activity of the immune system and bone remodeling.
Step-by-step explanation:
The immune system and bone remodeling are both regulated by hormones. Hormones such as parathyroid hormone (PTH), calcitonin, and growth hormone play a role in controlling the activity of immune cells and the processes of bone formation and resorption. For example, PTH promotes the release of calcium by stimulating osteoclasts, while calcitonin inhibits bone resorption. Growth hormone stimulates osteoblasts to create new bone.