The human rib cage forms a protective enclosure within the upper body, safeguarding organs such as the heart and lungs. Also known as the thoracic cage, this structure is positioned in the chest cavity and serves as a framework for the trunk. Beyond protecting internal organs, the rib cage also provides support for the shoulder girdle and facilitates respiration through its flexible design.
The Three Types of Ribs
The human rib cage consists of 12 pairs of ribs, classified by their anterior attachment to the sternum (breastbone). The first seven pairs are known as true ribs (vertebrosternal ribs), as their individual costal cartilages connect directly to the sternum. This direct connection provides stability to the upper part of the thoracic cage.
False ribs, typically pairs eight, nine, and ten, follow the true ribs. These ribs do not attach directly to the sternum. Instead, their costal cartilages join with the cartilage of the rib immediately above them, often merging with the cartilage of the seventh rib. This indirect connection contributes to the overall structure of the rib cage.
The final two pairs, ribs eleven and twelve, are floating ribs (vertebral ribs). These ribs lack any anterior attachment to the sternum or to the cartilages of other ribs. They terminate freely within the abdominal musculature, providing flexibility to the lower thoracic area.
Locating Your False Ribs
False ribs are rib pairs 8, 9, and 10. Posteriorly, these ribs articulate with their corresponding thoracic vertebrae, T8, T9, and T10. Their defining characteristic lies in their anterior attachment, where their costal cartilages do not reach the sternum independently.
Instead, the eighth rib’s cartilage usually connects to the seventh rib’s. The cartilages of the ninth and tenth ribs typically join the rib directly above them, forming a continuous cartilaginous arch that connects indirectly to the sternum via the seventh rib’s cartilage. This integrated structure forms part of the costal margin, defining the lower boundary of the rib cage.
To locate your false ribs, trace downwards from the sternum along the curve of your rib cage. Along the lower edge, you will feel where individual cartilages merge rather than directly connecting to the breastbone. This merging point, forming the costal margin, indicates the false ribs’ location. These ribs protect upper abdominal organs like the liver and kidneys, and provide flexibility for trunk movement.