Chapter 7.3, Problem 3AYLO

Summary Introduction

To discuss:

Histology, cell transformations, and tissue zones of the metaphysis; which zones and processes account for a child’s or adolescent’s growth in height.

Introduction:

Mineralization is a process (crystallization) that deposit phosphate, calcium and other ions (from blood plasma) in the tissues of the bone as hydroxyapatite. This process is initiated by the osteoblast by laying collagen fibers on the surface of the osteon. These fibers are coated with minerals that make the matrix hard. Only, if the concentration of the products (of above minerals) in the plasma reaches the critical value (solubility product), the hydroxyapatite formed. Sometimes, calcification is repressed by some inhibitors found in the tissue. This inhibitor is deactivated by osteoblast and it enables the precipitation of the salt in the matrix of the bone. The initially formed crystals perform like a “seed of crystals” which attract more phosphate and calcium from the plasma.