The skeletal system is a biological system responsible for providing structure and foundation in living organisms. The adult human skeleton is composed of 206 bones which can be classified as fused or individual bones supported and accompanied by ligaments, tendons, cartilages and muscles. The skeletal system performs a number of functions and each function is very important for the maintenance of homeostasis and optimal body function.
The skeletal system serves as a supporting structure of the human body. Not only does it support soft tissues, but also, it provides points of attachment for majority of the skeletal muscles. These bones contribute to the shape, alignment, and positioning of the body parts. For instance, the pelvis and its related supporting structures provide a floor for the pelvic structures. Another is the importance of the role of the ribcage for in its absence, the heart and lungs would collapse easily.
A major function of the skeletal system is that it mechanically protects the soft and delicate internal organs of the human body, thereby, reducing risk of injury to these structures. For example, the skull shelters the brain and the eyes, the spinal column protects the nerves, the fibrous discs between each vertebra as shock absorber and the rib cage encloses the heart and the lungs and protects major blood vessels. Other bones include clavicle and scapula which provide protection for the shoulders, the carpals and tarsals protecting the wrist and ankle, and the patella and ulna safeguarding the knees and elbows.
Bones, together with the joints create levers, allowing a wider range of motion in different directions and in different ways while movement is powered by the muscle tissues which are attached steadily to the bones. When the skeletal muscles contract and shorten, the bones are pulled, thus, creating a movement at the joint. The muscular system, skeletal system and joints present the most important mechanics for movement, all synchronized by the nervous system
The human skeletal system does not only function to provide support but also, importantly, it manufactures blood cells in the bone marrow. This process is called hematopoiesis or the formation of blood cellular components. This is a vital process carried on by red bone marrow or myeloid tissue. Primarily, this tissue is situated in the epiphyses, in the long bones, flat bones of the skull, in the pelvic bones and in the ribcage. In this tissue, new blood cells can be produced and those blood cells which are damages can be repaired. This bone marrow can produce red blood corpuscles, white blood corpuscles and other blood elements.
The skeletal system can be considered as a major reservoir for some minerals such as calcium and phosphorus. The bone matrix can store up calcium which is essential for the homeostasis of blood calcium concentration. When the blood concentration goes beyond the normal range, calcium moves out of the blood into the bones more rapidly, decreasing the concentration level of calcium in the blood usually to its homeostatic level. And when the body requires, bone can release minerals into the blood to facilitate the balance of minerals. Iron in ferritin, on the other hand can be stored by bone marrows.
The cells in the bones let loose of a hormone identified as osteocalcin, otherwise established as bone gamma-carboxyglutamic acid-containing protein. This is a noncollagenous protein found in bone and dentin which is thought to play a significant role in the fat deposition, metabolic regulation and bone-building and regulation of blood sugar as beta cells in the pancreas to liberate more insulin.
Storage of Chemical energy
As age advances, the red bone marrow changes into yellow bone marrow. This bone marrow primarily consists of adipose cells and a few blood cells. These fat cells are major chemical energy reserves.