how many individual ribs lack an anterior attachment
The floating ribs
The 11th and 12th pairs of ribs are called floating ribs because they are not attached to the sternum or connected to other ribs through cartilage. Instead, they only attach to the vertebrae in the back, leaving them free at the front. This lack of anterior attachment gives them a "floating" appearance, allowing for greater flexibility and movement in the lower ribcage.
the lungs are anterior to the ribs
Small 12th ribs, also known as "floating ribs," are the last pair of ribs in the human ribcage, typically not directly connected to the sternum. They are shorter than other ribs and only attach to the vertebrae at the back, providing minimal protection to the organs in the lower back. Their reduced size and lack of anterior attachment contribute to their flexibility and are thought to allow for greater movement of the torso. In some individuals, these ribs may be even smaller or absent altogether.
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
On the dorsal surface of the body, floating ribs attach to the vertebrae of the spine at the back. Unlike true ribs, they do not connect to the sternum or have any anterior attachment. Instead, they are only anchored at the vertebral column, providing some protection to the kidneys and other organs in the lower back.
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.
Vertebrosternal ribs, also known as true ribs, are the first seven pairs of ribs that attach directly to the sternum via their own costal cartilages. In contrast, vertebrochondral ribs, or false ribs, consist of the next three pairs (ribs 8-10) that do not attach directly to the sternum; instead, they connect to the costal cartilage of the rib above. Additionally, the last two pairs of ribs (ribs 11-12) are termed floating ribs as they have no anterior attachment to the sternum or cartilage. This structural difference contributes to their varying roles in the rib cage's function and stability.