Several systems work in tandem to support the human body’s function. The skeletal system provides the body with its structure, and it also protects internal organs and aids in movement. Bones are the primary contributors of the skeleton. Inner bone marrow is important to bodily functioning as well. Other components of the skeletal system include connecting ligaments, tendons, and joints.
Most vital organs are located in the chest, so components of the skeletal system located in this area are designed primarily for protection. The ribcage bones enclose organs ranging from the heart to the lungs. Another important protective bone encases the brain, the skull.
The components of the skeletal system that facilitate movement are primarily located in the arms and legs. These include the long femur and tibia of the leg and the humerus and radius of the arm. In addition, smaller bones like the metacarpals, metatarsals, and phalanges make up the fingers and toes. A different bone located in the head, the mandible, helps move the mouth.
Several other bones are also components of the skeletal system, and these bones join one part of the body to another. For example, the pelvic bone connects the upper body to the lower body. In contrast, the cervical vertebrae serve as the meeting place between the head and the upper body. Scapula and clavicle bones, on the other hand, help join the arms to the body.
While all bones provide some form of structural support and body design, long columns of bones found in the chest and back are especially vital in anchoring the human body and keeping it upright. In the back, the spine is comprised of a primary set of supportive bones known as vertebrae. These bones run from the neck to the pelvis. The bone at the front of the ribcage to which ribs are affixed is known as the sternum.
Bones must be held together by tough structures, so ligaments and tendons are crucial components of the skeletal system. These connective tissues are durable banded fibers that attach muscles and bones together and facilitate movement. Cushioning sacs called bursa are often found around tendons and ligaments, and these fluid-filled structures aid in softening strain and tension of the joints.
The points at which bones join together are known as joints. Hinge joints like those found at the elbow and the knee permit movements like bending and flexing. Twisting and turning are made easier by ball-and-socket joints, located in areas such as the shoulder. In order to prevent damage to bones as they move and rub together, a spongy substance called cartilage is found between many bones.
A more unusual duty is assigned to the inner bone area. Bones are not hollow, but rather are comprised of both hard external material and a softer internal substance called bone marrow. Marrow is partially responsible for blood cell production in the body.