Which type of ribs are not directly attached to the sternum?

False ribs are classified as those that are not directly connected to the sternum. Specifically, the false ribs include ribs 8 through 10, which have indirect attachments to the sternum via cartilage that connects with the rib above. Additionally, ribs 11 and 12 are considered floating ribs; they do not attach to the sternum at all. This distinction is essential when studying the ribcage structure and understanding how ribs articulate with the sternum and surrounding anatomical features.

True ribs, in contrast, are the first seven pairs of ribs that attach directly to the sternum, forming a continuous bony connection. Neck ribs and cervical ribs refer to anatomical variations rather than standard classifications of rib types in relation to the sternum. Therefore, focusing on the definition of false ribs clarifies why this is the correct choice for the question.