How many pairs of ribs articulate (directly or indirectly) with the sternum? * (1 Point) 10 12 7 5 24
The Correct Answer and Explanation is:
The correct answer is 7.
Explanation:
Ribs articulate with the sternum (the breastbone) through costal cartilage. Out of the 12 pairs of ribs in the human body, only the first 7 pairs (known as true ribs) directly articulate with the sternum. These ribs are connected to the sternum by their own individual costal cartilage.
Types of Ribs:
- True Ribs (1–7): These are the first 7 pairs of ribs. Each true rib has its own costal cartilage that connects directly to the sternum. Therefore, 7 pairs of ribs directly articulate with the sternum.
- False Ribs (8–10): These ribs do not connect directly to the sternum. Instead, their costal cartilages connect to the cartilage of the rib above them, which ultimately connects to the sternum. So, the 8th, 9th, and 10th ribs indirectly articulate with the sternum.
- Floating Ribs (11 and 12): These ribs do not have any anterior attachment to the sternum at all. Their costal cartilage ends in the musculature of the abdominal wall, so they do not articulate with the sternum directly or indirectly.
Therefore, the 7 true ribs are the ones that directly articulate with the sternum.
