Types of Bones

Bone Type

Description

Purpose

Bones

Long

Cylindrical, longer than they are wide. Composed mostly of compact bone with spongy bone at the ends.

Support body weight, facilitate movement, and act as levers for muscles.

Femur, tibia, fibula, humerus, radius, ulna, phalanges.

Short

Cube-shaped, as long as they are wide. Mostly spongy bone with a thin layer of compact bone.

Provide stability and support while allowing some motion.

Carpals (wrist bones), tarsals (ankle bones).

Flat

Thin, flattened, and often curved. Composed of two layers of compact bone with a layer of spongy bone in between.

Protect internal organs and provide large surface areas for muscle attachment.

Skull bones (frontal, parietal), sternum, ribs, scapula.

Irregular

Complex shapes that don’t fit into other categories.

Protect organs and support multiple functions like movement.

Vertebrae, sacrum, mandible, pelvis.

Sesamoid

Small, round bones embedded in tendons. Usually found near joints.

Reduce friction, act as pulleys for tendons, and protect tendons from stress.

Patella (kneecap), small sesamoid bones in the hands and feet.