This book describes the Bone, Functions, Diseases, Diagnosis and Treatment and Related Diseases
Bones are rigid organs that provide support and protection of the different organs of the body, produce red and white blood cells and store minerals.
Bone tissue is a form of dense connective tissue.
The bones that comprise the skeleton are all very much alive, growing and changing all the time like other parts of the body.
Almost every bone in the body is composed of the same materials:
The outer surface of bone is a thin, dense membrane that has nerves and blood vessels nourishing the bone.
The next layer is composed of compact bone.
It is the component a person sees when a person looks at a skeleton.
Inside the compact bone are many layers of cancellous bone, which appears a bit like a sponge.
Cancellous bone is not quite as solid as compact bone, but it is still very strong.
In many bones, the cancellous bone guards the innermost part of the bone, the bone marrow.
Bones have eleven main functions:
Mechanical Protection of internal organs such as the skull protecting the brain or the ribs guarding the heart and lungs.
Structure: The bones supply a frame to keep the body supported.
Movement using bones, skeletal muscles, tendons, ligaments and joints
Sound transduction in the mechanical action of hearing.
Blood production in the bone marrow
Metabolic - Mineral storage
Growth factor storage such as
a.Insulin-like growth factors
b.Transforming growth factor
c.Bone morphogenetic proteins
Fat storage: The yellow bone marrow functions as a storage reserve of fatty acids.
Acid-base balance
Detoxification: The bone tissues can also keep heavy metals and other foreign elements, eliminating them from the blood
Endocrine organ: The bone regulates phosphate metabolism by secreting fibroblast growth factor which works on kidneys to reduce phosphate re-absorption
Life and Death of a Bone Cell
My name is Bone Man the bone cell.
I was named Bone Man by my friends who feel that I am the main part of the bone.
Some of my friends called me Stone man because I hardly do anything just being stuck in the bone.
I started off as an osteoblast developing in the mesenchyme.
We osteocytes are the osteoblasts that have migrated into and become trapped and surrounded by bone matrix that they themselves produce.
We have many processes that reach out to meet osteoblasts and other brother bone cells for the purposes of communication.
Our functions include:
Formation of bone;
Matrix maintenance;
Calcium homeostasis.
The transformation from motile osteoblast to become us the mature bone cells takes about three days.
During this time we bone cells produce a volume of extracellular matrix three times its own cellular volume.
We osteocytes appear to be enriched in proteins that are resistant to hypoxia
This is due to our embedded location and restricted oxygen supply
Oxygen tension may regulate the differentiation of osteoblasts into us the osteocytes and any hypoxia occurring in us may play a role in disuse-mediated bone resorption.
We bone cells have a stellate shape
We have an average half life of 25 years (Full life of 50 years).
In a mature bone, our cells and their processes reside inside spaces called lacunae and canaliculi, respectively.
Our cells contain a nucleus and a thin ring piece of cytoplasm.
Remodeling or our bone turnover is the process of resorption followed by replacement of our bone with little change in shape
It occurs throughout a person's life
We bone cells die as a result of aging degeneration or necrosis, apoptosis and osteoclastic engulfment
Our bone cells will die and new bone cells will ta