TheRole of Human Skeleton
TheRole of Human Skeleton
Humanskeleton refers to the internal framework of a body. It includes allthe bones and joints. It is a major part of the body, and without it,it would be impossible to move, stand, or live. Contrary to otherbody organs, bones are muscular and firm, but they have their ownnerves, lymphatic vessels, and blood. An adult skeleton has twohundred and six bones. However, at birth, a child has over threehundred bones that gradually combine as the body grows up. There aretwo different parts of the skeleton. The appendicular skeleton is thebones from the clavicle to the phalanges, that is, the bones of theshoulder blades, hands, arms, feet, leg, and pelvis. The axialskeleton is the bones of the skull, neck, face, breast, ribs, and thespine. The main roles of human skeleton are to support, protect,assist in movement, mineral homeostasis, and to produce red bloodcells.
Humanskeleton together with muscular system supports the body, as well tokeep the internal organs in their respective place. The strong bonessuch as those the legs, pelvis, and spine support the weight of theentire body hence, enabling one to stand upright. Further, the bodycavities support the internal organs. For instance, the chest cavitysupports the lungs and heart, the skull supports the brain, and theabdominal cavity supports the digestive, internal reproductive, andthe urinary system organs.
Thehuman skeleton surrounds the internal organs with bones hence,protecting them from damage. According to Abernethy(2013),bones are living tissues that are strong and hard but flexible toresist breakage. Their strength comes from mineral content such asphosphorous and calcium. On the other hand, their flexibility is dueto collagen substance. The combination of bone strength andflexibility enables the skeleton to absorb any blow impact withoutbreaking. For instance, the skull, rib cage, and the spinal columnprotect the brain, heart and lungs, and spinal cord respectively.
Theligament holds together the skeletal bones while the tendons attachthe muscles to the skeleton bones to make a movement or hold them ina stable position. Different bones fit together at the joints to makedifferent types of movement due to the different shape of the boneand their position. The musculoskeletal system, the combination ofskeletal and the muscular system, enables the body movement andstability. The bone muscles contract to pull on the skeleton bone tomake body movement easy. The skeletal muscle pulls two or more bonestogether or apart while making a movement. For instance, the knee andthe leg bones come together to form a hinge joint that enables aperson to bend back and forth. Further, the shoulder and the hipboneare in different shape and their joints enable movement in multipledirections. Besides, the shape of the skeletal system eases movement.For example, the small foot and hand bones allow precise and detailedmovement and adaptation to all terrain.
Thehuman skeletal system performs mineral homeostasis that involvesstorage and release of minerals especially the calcium andphosphorous. Bone tissues store approximately ninety-nine percent ofthe calcium in the body. Upon demand, it releases it into the bloodthat distributes it to other parts of the body to maintain mineralbalance. Homeostasis leads to hypocalcemia or hypercalcemia, whichhas significant health consequence.
Insidelarge bones, there are spongy tissues known as red and yellow marrow.Red bone comprises of blood cells, fibroblasts, macrophages, andadipocytes within reticular fibers network. It is responsible for redblood cells production. In a day, it produces an average of twohundred million red blood cells. These cells then circulatelife-sustaining oxygen to other body tissues, as well as destroy theold cells. Additionally, red marrow produces white blood cells thatprotect the body from infections. Mainly, the red marrow exists inhips, breastbone, skull, ribs, arm, leg, and spinal bones. On theother hand, the yellow bone marrow that exists in the cavities oflong bones produces fat cells. However, the yellow marrow can convertto red marrow in case a body loses a large amount of blood in orderto make more blood cells. A newborn has only red marrow that isinvolved in hemopoiesis process, but as he or she grows, much of itchanges to yellow marrow.
Accordingto Abernethy(2013),the skeletal system serves as storage of various essential substancesto facilitate body growth and repair. For example, the bone tissuecell matrix acts like calcium and phosphate ions bank, and it isresponsible for storing and releasing them whenever the body needsthem. In addition, the hollow medullary cavity in the long bonescontains the yellow bone marrow that stores energy in lipids form andred bone marrow that stores iron in ferritin molecule form. Further,the yellow bone marrow stores fat and triglycerides in its adiposetissue, and later releases them to the body as a source of energy.
Abernethy,B. (2013). Biophysicalfoundations of human movement.Champaign, IL: Human Kinetics.