The skeletal system is made up of 206 bones, joints and ligaments that connect bones to muscles.
The skeleton supports and holds up the human body.
The skeleton protects internal organs of the body.
Vertebrae: spinal cord
Ribs, sternum and spine: lungs, heart, blood vessels
Clavicle and scapula: shoulder
Ilium and spine: digestive organs (stomach, intestines, liver, pancreas)
Patella and ulna: knee and elbow
Carpals and tarsals: wrist and ankle
The red and yellow marrow in the middle of long bones makes red blood cells.
Bones store calcium and iron.
Bones have hormones that control blood sugars and fat deposits.
The skeletal system, along with the muscular system, allow the body to move freely. Joints are places where two or more bones meet. Hinge joints are found in the knee and elbow and allow the bones to move back and forth like a door on a hinge. Ball and socket joints are found in the hips and shoulders and allow the bones to rotate in different directions. The pivot joint is where the skull and vertebrae connect and allow the head to move around.
Bone Marrow Diagram