We have often read about various aspects of our bodies from a structural perspective. We learn about broken bones, back pain, skull fractures, and knee injuries, but what exactly comprises our skeletal system? What are the key elements of our human framework? The primary players are the bones, ligaments, and tendons that are integrated into a mechanism known as the skeleton that provides for movement, stability, protection, and growth of the body.
Did you know that there are about 206 bones in the human body? (That is a lot of pieces to potentially break!) Bones act as connective tissue within the body. Bones are essentially made of a mineral compound called calcium phosphate, which is a hard substance, with a smaller amount of collagen. The collagen cells allow for some degree of elasticity when a bone undergoes trauma.
There are two kinds of bones: the cortical bones and the cancellous bones. The cortical ones are denser and more compact, comprising a large part of the skeleton frame. The longer bones in the body, for example, are cortical, such as the femur. The long bones are hollow and filled with yellow marrow. At then end of the long bone is the epiphysis. The epiphysis is made of cancellous bone cells. The marrow in this portion is red. Red marrow generates the red blood cells we need, and yellow marrow creates the white blood cells we need.
Ligaments are responsible for connecting bones to other bones, thereby creating a joint, a flexible structure that aids in movement and the bearing of weight and external forces applied to it. Made of collagen, they are formed into short and fibrous bands. Every ligament in the body is necessary for efficient physical movement. Two ligaments of great importance to the framework are the anterior cruciate ligament (ACL), which connects the upper leg to the lower leg, and the ulnar cruciate ligament (UCL), a key structure of the elbow.
Tendons, much like ligaments, are strong, fiber-like connectors. Instead of connecting bone to bone, however, they serve to connect the muscle to the bone, which in turn provides stability and a great amount of resistance to external forces.