Gastrointestinal: Adjective referring collectively to the stomach and small and large intestines. The commonly used abbreviation for gastrointestinal is GI. (Outside of medicine, GI can also stand for galvanized iron, general issue or government issue-as in GI Joe).
Before the extracellular matrix is calcified, the tissue is called osteoid (bone-like) tissue. When the concentrations of calcium and phosphate ions rise high enough, they are deposited into the extracellular matrix, and the bone calcifies.
Osteoblast (from the Greek combining forms for  bone , á½ÏÏÎ­Î¿-, osteo-and Î²Î»Î±ÏÏÎ¬Î½Ï, blastanÅ germinate) are cells with single nuclei that synthesize bone.uring active bone formation, the surface layer of osteoblasts consists of cuboidal cells, called active osteoblasts. When the bone-forming unit is not actively synthesizing bone, the surface osteoblasts are flattened and are called inactive osteoblasts.