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What is osteoporosis

Osteoporosis literally means porous bone.

Our Bones

Normal bones are composed of a shell of compact or solid bone surrounding connecting plates and rods of bone within which lie the bone marrow. The thickness of the outer shell of compact bone varies in different parts of the skeleton, being thicker in the bones of the skull, arms and legs than in the spine. Much of the strength of the skeleton is the result of the compact bone but the spongy bone also makes an important contribution. Bone is made up mainly of a protein called collagen and bone mineral, which contains calcium.Osteoporosis

Our bone is a living tissue which needs to be constantly renewed to keep up its strength. All the time old bone is being broken down and replaced by new stronger bone. If this process of remodelling did not exist our skeleton would suffer from fatigue. There are two main types of cell in bone, the Osteoclasts which destroy old bone and the Osteoblasts which make new bone, these cells are formed in the bone marrow. As we get older the Osteoclasts become more active and the Osteoblasts less active so more bone is removed and less formed.

Osteoporotic Bones

In Osteoporotic bone the amount of compact and spongy bone is reduced. Thinning of the bone greatly reduces is strength and and increases the likelihood of fracture.

Peak Bone Mass

Our bones grow with us during childhood and adolescence and become more solid and by our mid twenties the amount of bone in the skeleton has reached its maximum, this is known as the peak bone mass. Peak bone mass varies among individuals and is generally higher in men than women and is greater in those with a large body frame than in small thin individuals.

The peak bone mass is very important in determining whether an individual is at risk from osteoporosis later in life. If it is low then even small amounts of bone loss may result in fracture whereas if it is high, an individual will be protected from osteoporosis. The factors that determine peak bone mass are a strong genetic influence, calcium intake and physical exercise and hormone levels.osteoporosis affects

Bone Loss

In both men and women age related bone loss begins around the mid forties and continues throughout life. For women, around the time of menopause, the rate of bone loss increases for a few years and because women have less bone to start with and live longer than men they are more at risk from osteoporosis.
- Bone is composed mainly of protein and bone mineral, which contains calcium.