After endochondral and intramembranous ossifications, homeostasis of bone tissue is maintained through the continuous remodeling actions of osteoblasts and osteoclasts. Normally, the osteoclasts reabsorb (breakdown) bone tissue, while osteoblasts replace (build) bone tissue. These opposing processes known as resorption and deposition are well regulated, so that the total bone tissue mass generally remains nearly constant.

 However, there are various disorders and or diseases that are characterized by an imbalance between the activities of the osteoclasts and osteoblasts. In other words, there is an excess of osteoclasts activities which outpace the activities of the osteoblasts and vice versa.

 Based on your knowledge, curiosity, and your search for further understanding of the physiology of bone growth and remodeling:

1. List any TWO diseases /disorders that result form increase activities of osteoclasts and diminish activities of osteoblasts. Choose ONE disease/ disorder from your list, and explain the physiological factors or processes responsible for the signs and /or symptoms that typify it.

2. List any TWO diseases /disorders that result form increase activities of osteoblasts and diminish activities of osteoclasts. Choose ONE disease/disorder from your list, and explain the physiological factors or processes responsible for the signs and /or symptoms that typify it.