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.
Loin
The loins (or: lumbus) are the sides between the lower ribs and pelvis, and the lower part of the back. It is often used when describing the anatomy of humans and quadrupeds (such as horses, pigs or cattle). The anatomical reference also carries over into the description of cuts of meat from some such animals, e.g. tenderloin or sirloin steak. 
In human anatomy the term "loin" or "loins" refers to the side of the human body below the rib cage to just above the pelvis. It is frequently used to reference the general area below the ribs. While the term "loin" is generally not used in medical science, some names of disorders do contain it.