Final answer:
The statement that all ribs are true ribs is false. Only the first seven pairs of ribs are considered true ribs because they are the only ones that attach directly to the sternum via their costal cartilage.
Step-by-step explanation:
The statement 'All ribs are true ribs' is false. Human ribs are divided into groups based on their connection to the sternum. The first seven pairs are referred to as true ribs, also known as vertebrosternal ribs, because they attach directly to the sternum via their costal cartilage. The next three pairs (ribs 8-10) are classified as false ribs or vertebrochondral ribs, as their costal cartilages do not attach directly to the sternum but instead to the cartilage of the rib above. Lastly, the 11th and 12th pairs are known as floating ribs, which do not attach to the sternum at all and end within the musculature of the abdominal wall. Therefore, only rib pairs 1-7 can be accurately described as true ribs.