BONE BUILDING CELLS
Bone can be defined as the rigid endoskeleton of calcium phosphate and forms the endoskeleton of the body . The skeletal system formed by the bones is the unit that is associated with the muscular system that enables movement. It also is involved in supportingm protecting variopus organs in the body, is the site of synthesis of blood cells by haemopoeiesis and also as a storage of minerals like calcium. Bones have diverse structure in accordance with a diversity in function. ther e are about 206 bones in the body (excluding the ossicles) and the bone consists of osseous tissue along with endosteium, periosteium ,nerve, blood vessels, lymph etc. Bone building cells are cells the osteoblasts ,osteoclasts, osteocytes etc.
General structure of bone :
Bone is a type of connective tissue consisting of a hard outer layer of compact bone tissue (dense bone.) with a 5% to 10% porosity producing the smooth white appreaance and accounting of about 80% of adult bone mass.Internal to it lies the trabecular bone or the cancellus or spongy bonm with trabecular networks and porus in nature.It is basically a network of rod and plate like filaments that allows space for angiogenesis or growth of blood vessels
.Trabecular bone makes up about 20% of adult bone mass but has a surface area nearly 10 times with a porosity of aout even 90%.The cancellous bone consists of haversian sites and osteons .Besides , the blood is sourrounded by bone in the compact bone but it is reverse in cancellous bone.
In the bone , there are 5 types of bone building cells:
These are immaure cells that act as progenitors for osteoblasts and may undergo division.
BONE LINING CELLS
Osteoblast c ells in minimal activity ,almost inert , lining the bone .