Forming the major portion of the skeleton, bones are a dense and calcified connective tissue. There are more than 200 in the human body.
Bones give the body structure and protect all of our internal organs.
Bones are a constantly changing tissue that has several functions. They protect our delicate internal organs and they store bone marrow and calcium. They have two shapes: flat (ex. the skull and the vertebrae) and tubular (ex. thighbones and arm bones). All bones have basically the same structure.
The hard outer part consists mostly of proteins, such as collagen. The marrow in the centre is softer and less dense than the rest and contains cells that produce blood cells. Blood vessels supply blood, and nerves surround the bone.
The skeleton undergoes an ongoing process known as remodeling. In this process, old tissue is gradually replaced by new tissue. The body is completely reformed about every 10 years. To maintain density, the body requires an adequate supply of calcium and other minerals and must produce the proper amounts of several hormones, such as the growth hormone, estrogen, and testosterone.
The skeleton is surrounded by a thin membrane called the periosteum. We can feel pain because of nerves located mostly in the periosteum and receive blood through blood vessels that enter through it.
It is important to keep your skeleton strong with regular exercise and a diet high in calcium to avoid potential fractures and reduce the risk of osteoporosis.