Bodies in Balance
The Skeletal System
The human skeleton is mostly made up of bones. Bones are composed of four different types of cells, which are referred to as osteogenic (type of stem cells), osteoblast (bone forming cells), osteoclast (bone destructing cells), and osteocytes (transports bone containing essential minerals such as calcium and phosphate into the extracellular matrix). Further, it promotes the production of red blood cells in the bone marrow. The bones articulate at joints. The human body has 206 bones which are organized in the skeleton. It functions as a protection of vital organs, forms the framework of the body, and supports vital body functions, such as physical movement, as well as communication. The skull encases the soft tissue in the human brain, the rib cage and sternum, shield the heart and lungs from the surrounding environment, and the pelvis safely houses our internal organs. Humans have an endoskeleton which is inside the body, and is split into two main divisions, the axial skeleton and the appendicular skeleton. The axial skeleton consists of 80 bones and comprises the skull (facial bones and cranial bones), hyoid bone, , vertebral column, auditory ossicles and the thorax (the sternum and the rib bones form the thorax). The appendicular skeleton consists of 126 bones and comprises the shoulder girdles (the scapulae and the clavicle on each side of the bone form the shoulder girdles), the upper extremities (arms, wrists and hands), the pelvic girdle (including the coxal bones ilium, ischium and pubis) and the lower extremities (legs, ankles and feet), (Juvekar, 2013) (Holadia, 2012).
There are four different categories of joints that are known as fibrous, cartilaginous, bony and synovial. Fibrous cartilage is found in the sutures of the cranium, collagen fibers reach from one bone to unify with another and bind adjacent bones together, which prevents movement of the bones. Cartilage is the tough but flexible tissue that...