- The bones of the skull, spine, ribs and sternum comprise the axial skeleton, as they form the body's "axis." The skull is made up of cranial and facial bones. The cranial bones insulate the brain, and the facial bones form the structure of the face. The sternum is sometimes called the breastbone and is located vertically in the center of the chest. The ribs connect to the sternum to form the ribcage, which protects the heart and lungs. The spinal column is made of 33 bones known as vertebrae. The vertebrae are labeled according to their position in the column. Moving from top to bottom, the terms are as follows: cervical, thoracic, lumbar, sacrum and coccyx vertebrae.
- The appendicular skeleton is formed by the bones that are attached to the central axial skeleton. The upper extremities include the arm and hand muscles. The humerus extends from the shoulder to the elbow, and the radius and ulna are located in the forearm. Twenty-seven bones comprise the wrist, palm and fingers. The wrist contains the carpal bones, the palm contains the metacarpals, and the fingers are made of bones known as phalanges. The next division of the appendicular skeleton is the shoulder girdle, which is formed by the clavicles (collarbones) and scapulas (shoulder blades). A little lower down, the pelvic girdle is made of the coxal bones (hip bones), and the sacrum. The sacrum is the location where the coxal bones meet. The final division of the appendicular skeleton is the lower extremities. The femur is the name for the thigh bones, which run from the hips to the knees. The kneecap is known as the patella, and the lower leg contains the tibia and fibula. The foot is made of the ankle, instep and toe bones, which total 26. The ankle bones are termed tarsals, the instep is made of metatarsals and the toes are called phalanges.
next post