the second pair of ribs
The true ribs (pair 1-7) are connected to the sternum by way of the costal cartilages, a type called hyaline. Pair 8-10 are called floating ribs and they also attach to the sternum but use the same cartilage as 7.
The second pair of ribs or the True ribs
There are twelve pair of ribs. The first seven ribs are true ribs because they have direct attachment to the sternum. An additional three pair of ribs have indirect attachment to the sternum meaning that they attach to other structures that attach to the sternum. The last two ribs are called floating ribs because they do not attach to the sternum at all. Because the floating ribs do not attach to the sternum they are prone to injury.
Horses have 18 pairs of ribs, but the first pair are classified as "true" because they attach directly to the sternum. The remaining 16 pairs are considered "false" ribs because they do not directly attach to the sternum, instead connecting to the costal cartilage of the 8th rib.
Floating ribs are a type of false ribs. False ribs are ribs that do not directly attach to the sternum through cartilage, and they include both floating ribs (ribs 11-12) and ribs 8-10, which are attached to the sternum indirectly through cartilage.
No, not all ribs directly articulate with the sternum. Ribs 1 to 7 directly articulate with the sternum, while ribs 8 to 10 indirectly articulate with the sternum through the costal cartilages of the ribs above them. Ribs 11 and 12 are floating ribs that do not articulate with the sternum at all.
The ribs and sternum are best classified as the rib cage. Most of the ribs and sternum consist of bone.
There are typically seven pairs of ribs that directly connect to the sternum, forming the rib cage. These are known as true ribs.
According to Ross and Wilson Anatomy and Physiology, 2 pairs
Ribs 11 and 12 do not attach anteriorly to the sternum.
Ribs 8 to 10 are attached individually to the sternum by way of the costal cartilage. Ribs 1 to 7 are attached directly to the sternum, while ribs 11 and 12 are floating ribs without any attachment to the sternum.
Only the true ribs are attached to the sternum the false ribs (3) and the floating ribs (2) are not directly attached. The flalse ribs are attached indirectly via cartillage and the floating ribs are not attached at all.