FALSE OR ASTERNAL RIBS Meaning and
Definition
-
False or asternal ribs, also known as floating ribs or vertebral ribs, are a set of ribs found in certain vertebrates, including mammals, that differ from the typical structure of true ribs. These ribs are referred to as "false" or "asternal" because they do not directly attach to the sternum or breastbone like the true ribs.
In mammals, the false or asternal ribs are usually the last two pairs of ribs, namely the eleventh and twelfth ribs. Unlike the other ribs in the ribcage, these ribs are not connected to the sternum by costal cartilages. Instead, they are only attached to the vertebral column. This lack of attachment to the sternum allows for more flexibility of the ribcage, promoting better movement during respiration and allowing for the expansion of the thoracic cavity.
The false or asternal ribs are generally shorter and less curved than the true ribs. They are usually free-floating, meaning they are not directly connected to each other or to any other structure. Some function as protection for the kidneys, while others contribute to the flexibility of the thoracic region.
Overall, false or asternal ribs play a significant role in promoting mobility and flexibility in the ribcage, allowing for better respiratory movements and protecting vital organs. They are an important feature of the skeletal system in certain vertebrates, including humans.
