Parts & Functions of the Skeletal System

The human skeleton

The skeletal system is the frame work of the body and provides support and protection. The human skeletal system is made up of 206 bones which rely on bone marrow, tendons and ligaments to function.

Bones

All bones are made up of two types of tissue: compact, or dense, tissue and spongy tissue. There are four types of bones: long bones (like those in the arms and legs), short bones (like those found in the ankles and wrists), flat bones (like ribs and those in the skull), and irregular bones (like the vertebrae in the spine).

Bone Marrow

All bones are filled with a spongy material called bone marrow. Bone marrow is either red or yellow. Red marrow is primarily found in flat bones. Yellow bone marrow is primarily made of fatty bone cells and is found in long bones.

Ligaments

Ligaments are bands of tough, fibrous material that are used to connect bones to create joints.

Tendons

Tendons are similar in structure to ligaments but are used to connect muscles to bones. A joint strain occurs when a tendon is damaged.

Joints

Joints are formed at any point where two bones connect. Joints can be movable, like ankles and knees, or they can be fixed like the joints in the skull.

References

• Minnesota State University eMuseum: Skeletal System
• "Human Anatomy & Physiology;" Elaine Nicpon Marieb and Katja-Hoehn; 2006