What are typical ribs?

Ribs are elongated and flattened bones that form a major part of the thoracic wall, all of which are a total of 12 ribs. There are true ribs (ribs 1-7), false ribs (ribs 8-10), and floating ribs (ribs 10-12). There are also typical (ribs 3-9), and atypical ribs (ribs 1,2,10,11,12). The typical ribs and atypical ribs are differentiated from each other based on their structural anatomy. Atypical ribs do not have the common features that are found in most of the ribs hence they are called “atypical.” While typical ribs are composed of the important landmarks of what would be considered as a “typical” rib and all share a common structural floor plan. Typical ribs (ribs 3-9) are elongated, slightly twisted, and flat bones which have a dull upper border, and sharp lower border. Typical ribs share common features such as the body, tubercle, neck, head, angle and costal groove.