How bones are formed.

Bones begin life as cartilage. As the young baby develops in the mother's womb, the skeletal system becomes organised into a framework of cartilage. Before birth, there is a certain amount of hardening of the limb bones to allow the animal to stand shortly after delivery. However, the greater part of the skeleton is cartilage at birth. After birth, hardening of all parts of the skeleton begins. This process continues throughout life until, in old age, very little cartilage is left and the bones are old and brittle. The process of hardening cartilage into bone is called ossification.


Ossification is achieved by bone-forming cells called osteoblasts (osteo- means "bone" in Greek). The old osteoblasts produce bone tissue, which is also called osteotissue, and also secrete the enzyme phosphatase which allows calcium salts to be deposited in the newly formed bone tissue. This makes the tissue hard or bone-like.


The osteoblasts are connected by a system of tiny canals called canaliculi which bring tissue fluid to each osteoblast. The canals and special cells make a network which forms the frame of the bone. The newly made bone tissue is laid down on this mould and, in time, becomes calcified or hardened.


Once the bone tissue is hardened and mature, the osteoblast change into osteocyctes (mature bone cells). They sit in small cavities called lacunae within the calcified or hardened bone tissue. The system of canals still connects the lacunae and now serves to carry tissue fluid that is essential for the maintenance of life of the osteocytes.

Who Needs to Understand Bones?
A knowledge of bones is important to not only doctors, but also anyone working in allied health industries. Fitness and sporting professionals need to also understand bones (along with muscles), in order to properly understand and manage human movement. Nutritionists also need to understand bones, in order to properly manage diet.
Biology teachers teach people about bones; physiotherapists help people rehabilitate after bone injuries, and first aid officers need to understand the bone structure of the human body in order to help and not hinder in an emergency.
In today's world; where so many people spend much of their lives sitting, or focused on a computer screen; the potential for chronic bone and muscle problems has greatly increased. An understanding of bones and muscles can help you better manage yourself; those around you; and for those who are involved in health, safety or fitness professions; can further your career prospects.
Learn More about Bones and how they move
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