Bone

• Bone is a connective tissue. Consisting by weight of about one-third collagen matrix (osteoid) and two-thirds mineral, it contains three types of cells---osteoclasts, osteoblasts, and osteocytes, according to the book "Human Physiology, Eighth Edition," by Arthur Vander et al.
  
  

Osteoclastic Activity

• By secreting hydrogen ions and certain enzymes, osteoclasts dissolve crystals and digest osteoid, breaking down previously formed bone, note Vander et al.
  
  

Osteoblastic Response

• Stimulated by gravity and muscle tension, osteoblasts respond to osteoclastic activity by laying down new collagen matrix. Once surrounded by calcified matrix, osteoblasts are called osteocytes, observe Vander et al.
  
  

Remodeling

• Give and take between osteoblasts and osteoclasts constantly replaces old bone tissue with new---a process called remodeling. Reflecting bone's role in providing support, remodeling distributes bone matrix along lines of mechanical stress, according to the book "Principles of Human Anatomy, Ninth Edition," by Gerard Tortora.
  
  

Balance

• Osteoblasts and osteoclasts maintain a delicate balance. Too much of one over the other can result in bone weakness or malformation, observes Tortora.