how many individual ribs lack an anterior attachment
The floating ribs
the lungs are anterior to the ribs
Floating ribs (ribs 11 and 12) do not articulate with the sternum directly but are attached only to the thoracic vertebrae in the back. They are considered "floating" because they lack an attachment to the sternum or cartilage.
The ribs
In the posterior position the ribs articulate on individual vertebrae of the spine. I the anterior position they converge on the sternum. There is no bone in the centre of cage made by the ribs.
False ribs are ribs that have no direct attachment to the sternum (breast bone).
False
Hahahah no. But there are 4 floating ribs (2 each side). These are the bottom of the 12. Their posterior attachment is to T11 and T12 and they have no anterior atachment, they are not connected to the sternum by cartilage.
Ribs are classified according to their attachment to the sternum. The first seven pairs of ribs attach directly to the sternum and are called true ribs. Ribs 8-10 have cartilage that attaches to the cartilage of the seventh rib and are called false ribs. The eleventh and twelfth ribs do not attach to the sternum and are called floating ribs.
It's located on your upper ribs, just on the side of your chest
Costal cartilage
The scalenus anterior and the scalenus medius all insert into the first rib (the scalenus posterior inserts into the second rib). They originate from cervical vertebrae two to cervical vertebrae seven (C2 - C7). Each of the scalene muscles has several points of origin, which look like fingers from your spine.