Organization of the Skeleton
The adult human skeleton is a framework of 206 bones and is anatomically divided into two parts, the axial skeleton and the appendicular skeleton.
The core of the skeleton is referred to as the axial skeleton. It consists of 80 bones, including the skull bones, hyoid bone, vertebrae, ribs, and sternum.
Attached to the axial skeleton is the appendicular skeleton. It is formed by 126 bones, including the pectoral girdle (clavicle and scapula), bony pelvis (os coxa, sacrum, and coccyx), and upper and lower limbs (humerus, radius, ulna, carpals, metacarpals, hand phalanges, femur, tibia, fibula, tarsals, metatarsals, and foot phalanges).
Functionally, the bones provide support and protect fragile organs of the body such as the brain, spinal cord, heart, and lungs.
Additionally, the bumps, ridges, and grooves on the surface of bones serve as attachment sites for the skeletal muscles. When the muscles contract, they produce movements of the head, neck, trunk, and limbs.