10. Which bone in the following image is part of the axial skeleton?
Answer: A
The sternum is part of the axial skeleton.
The sternum is classified as a component of the axial skeleton, which includes the bones that form the long axis of the body, such as the skull, vertebral column, and rib cage.
A) Scapula
The scapula, or shoulder blade, is part of the appendicular skeleton, which consists of the bones of the limbs and the girdles that attach them to the axial skeleton. Therefore, it is not a part of the axial skeleton.
B) Sternum
The sternum is indeed part of the axial skeleton. It serves as a central bone to which the ribs attach and plays a critical role in protecting the thoracic cavity.
C) Humerus
The humerus is the bone of the upper arm and is classified as part of the appendicular skeleton. It connects the shoulder to the elbow, making it unrelated to the axial skeleton.
D) Femur
The femur, or thigh bone, is also part of the appendicular skeleton. It is the longest bone in the body and connects the hip to the knee, thus not being a part of the axial skeleton.
Conclusion
The sternum is the only option that belongs to the axial skeleton, serving an essential structural role in the thoracic region. In contrast, the scapula, humerus, and femur are all components of the appendicular skeleton, which focuses on limb attachment and mobility rather than the central axis of the body.