Key terms
Appendicular skeleton
The part of the skeleton that includes the arms, legs, shoulders, and hips.
Diaphysis
The long, middle section of a long bone.
Fontanels
Soft spots in a baby’s skull where bones haven’t finished joining
Medullary canal
The cavity inside a long bone that contains marrow.
Periosteum
The outer covering of a bone.
Axial skeleton
The main framework of the body made up of the skull, spine, and rib cage.
Endosteum
The lining inside the medullary canal of a bone.
Foramina
Small openings in bones that allow nerves and blood vessels to pass through.
Metacarpals
The hand bones between the wrist and fingers.
Phalanges
The bones of the fingers and toes.
Carpals
The small bones that make up the wrist.
Epiphysis
The end part of a long bone where growth occurs.
Humerus
The upper arm bone.
Metatarsals
The foot bones between the ankle and toes
Radius
The forearm bone on the thumb side.
Clavicles
The collarbones that connect the sternum to the shoulders.
Femur
The thigh bone and the longest bone in the body.
Joints
Places where two bones meet.
Os coxae
The hip bones.
Red marrow
Bone marrow that makes blood cells.
Cranium
The part of the skull that protects the brain.
Fibula
The smaller bone of the lower leg.
Ligaments
Tough tissues that connect bone to bone.
Patella
The kneecap.
Ribs
The bones that form the chest and protect the heart and lungs.