Explain how many structural layers exist in the bone how do

Explain how many structural layers exist in the bone, how do they differ in microstructure and shape? what is the intended purpose of each layer? Answer the following questions: How does the mass of the cortical bone differ from the mass of the cancellous bone (how many times, magnitude)? How does structure of the cancellous bone in the femoral bone varies with respect to the height at the transverse plane

Solution

Answer=Bones are composed of substance called Hydroxyapatite which is made up of calcium phosphate.

All bones in body have three layers of cells

Osteoblasts,Osteocytes & osteoclasts

Osteoblast= Are called as bone builders .it produce a matrix is eventually mineralised or hardened

Osteocytes= Are mature bone cells present inside matrix

Osteoclast= are called as bone destroyers

Osseous or bone tissue= are of 2 types

1]Compact bone = is denser & forms outer layer

2] cancellous bone = Forms inner layer .it is made up of trabeculae,& in some bones red marrow located here

Looks like as asponge called as spongy bone

Bones have 2 membranes=

Periosteum= lines the outer surface

It has 2 layers Fibrous layer contain fibroblast & cambium layer producesosetoblast

It also has nerve endings

Endosteum= lines medullary cavity of bone

Cortical bones account for 80% of total bone of mass of adult human skeleton

Cancellous bones account for 20% of total bone mass