The ribcage:

The ribcage is an essential part of the skeletal system that protects the vital organs in the chest. It is made up of several bones called ribs, which are curved and attached to the spine at the back and the sternum (breastbone) at the front. The number of ribs in the ribcage can vary from person to person, but the most common number of ribs is 24, with 12 pairs.

The number of bones in the ribcage:

The correct answer to the question is (d) 24, as there are 24 individual ribs in the ribcage. These ribs are organized into 12 pairs, with each pair attaching to the thoracic vertebrae at the back and the sternum at the front. The ribs are connected to the thoracic vertebrae by small joints called costovertebral joints, and to the sternum by cartilage called costal cartilage.

Key points:
- The ribcage protects vital organs such as the heart and lungs.
- The ribs are curved bones that are attached to the spine and sternum.
- The most common number of ribs in the ribcage is 24, with 12 pairs.
- Each rib is connected to the spine by costovertebral joints and to the sternum by costal cartilage.

Importance of the ribcage:

The ribcage plays a crucial role in protecting the organs in the chest, including the heart and lungs. The ribs act as a protective cage, preventing direct impact on these vital organs and reducing the risk of injury. Additionally, the ribcage provides support and structure to the chest, allowing for proper functioning of the respiratory system and facilitating movements such as breathing.

Conclusion:

In conclusion, the ribcage consists of 24 individual ribs organized into 12 pairs. The ribs are curved bones that protect vital organs and provide support to the chest. The ribcage is an important part of the skeletal system and plays a crucial role in protecting and supporting the body.

The rib cage consists of the 12 thoracic vertebrae and the 24 ribs, in addition to the sternum.
So,
Ans- d)24