The axial skeleton includes the head, neck, and trunk. The spinal column, also referred to as the backbone, is also divided into different sections. There are seven vertebrae in the neck, twelve thoracic vertebrae make up most of the back, and 5 lumbar vertebra help form the lower back. The sacrum are a series of bones in childhood but fuse together into one piece usually by the age of 25. The bottom of the backbone is called the coccyx.
Attached to the spinal column is the rib cage. Twelve ribs on each side – some attached and some ‘floating’ – help protect the heart and lungs. The vertical bone on the front of the rib cage is called the sternum.
The appendicular skeleton includes the arms and legs of the human body.
The shoulder girdle includes the scapular (shoulder blade) plus the humerus (upper arm) and the clavicle (collarbone). There are two bones in the lower arm, the radius and the ulna. The wrist contains the carpus bones and the hand bones are referred to as metacarpus. Phalanges are the bones in our fingers.
Human legs are set up similarly as human arms. The pelvic girdle includes the pelvis and sacrum. The thigh bone is called the femur and the two bones in the lower leg are the tibia and fiblua. The front and back of the foot contain the tarsus and metatarsus, respectively and, like the fingers, the toes are called phalanges.
The human skeleton provides structure for the human body as well as the ability to move and protection for vital organs.
Bones are connected to other bones by fibrous material called ligaments while tendons connect bone muscle which acts to move the bone. These connections occur at joints, most of which are movable. The one joint that is immovable is the skull which protects the all-important brain.