Rib cage
The rib cage is the arrangement of ribs attached to the vertebral column and sternum in the thorax of most vertebrates, that encloses and protects the heart and lungs. In humans, the rib cage, also known as the thoracic cage, is a bony and cartilaginous structure which surrounds the thoracic cavity and supports the shoulder girdle to form the core part of the human skeleton. A typical human rib cage consists of 24 ribs in 12 pairs, the sternum and xiphoid process, the costal cartilages, and the 12 thoracic vertebrae.
Sex differences in human physiology
The following further generalizations have been made regarding male-female skeletal differences:Studies have measured male and female canine and other teeth, yielding different results as to which sex has the larger, where observed differences in size are small. Finally, contrary to popular belief, males and females do not differ in the number of ribs; both normally have twelve pairs.