Skeletal System Your Skeletal System is all of the bones in the body and the tissues such as tendons, ligaments, and cartilage that connect them. The skeletal system help to support, protect, and provide movement for the human body.

Major Organs of the Skeletal System Bones, cartilage, tendons, and ligaments are the organs of the human skeletal system. Bones are hard, rigid form of connective tissue constituting most of the skeleton and are made mostly of calcium salts. Cartilage is tough, elastic, fibrous connective tissue and is found in joints, nose, outer ear, and larynx. Tendons are a band of tough tissue that attaches a muscle to a bone. Ligament is a sheet or band of tough, fibrous tissue connecting bones or cartilages at a joint or supporting an organ.

Bone Functions The functions of bones include the following: Support- bones support the framework of the skeleton Protection-bones protect internal body’s organs Assisting in Movement- when muscles contract bones are made to move Storage of Minerals-bone tissues store minerals, such as, Calcium and Phosphorus. When necessary bones release minerals into blood. Production of blood cells- Bone marrow is produced. Red bone marrow inside larger bones and white blood cells and platelets. Storage of Chemical Energy- With age some bone marrow changes from red to yellow a chemical energy reserve is crucial for proper function.

Illustration of Bone Structure

Joints and Ligaments Ligaments are Fibrous tissues connecting bones to other bones. Joints are where two or more bones make contact.

Bones as Levers Your limbs resemble a machine, the muscle pulling on a bone resembles a lever. Most bones in arms and legs act as levers, which are powered by muscles. A lever is a rod that is able to rotate about a fixed point, in the skeletal system this is at the fulcrum formed by the joint. Any force applied is in the form of effort. A downward force is called the load or resistance. Any contraction of muscle is the effort and the opposing part is the resistance or load. Bones of the body act as levers which create mechanical advantage of strength and speed.

Vocabulary Skeletal System provides the framework which supports the body and maintains its shape. Cartilage is a flexible connective tissue found between bones. Joint is the location at which two or more bones make contact. Ligaments are the fibrous tissue that connects bones to other bones. Compact Bone is one of two types of osseous tissue that form bones. This bone facilitates bone’s main functions to support whole body, protect organs, provide levers for movement, and store and release chemical elements, mainly calcium. Spongy Bone is one of two types of osseous tissue that forms bones. This bone has higher surface area but is less dense, softer, weaker, and less stiff than compact bone. It is found at the end of long bones, is proximal to joints, contains red bone marrow where hematopoiesis, the production of blood cells, occurs.