Which of the following is not a part of the appendicular skeleton?
A.
Clavicle.
B.
Rib.
C.
Femur.
D.
Scaphoid.
The correct answer and Explanation is :
The correct answer is B. Rib.
The appendicular skeleton consists of the bones of the limbs and the supporting girdles. It includes the bones of the upper limbs (arms) and lower limbs (legs), as well as the pectoral girdle (shoulder girdle) and the pelvic girdle. Specifically, it encompasses:
- Clavicle (collarbone): Part of the pectoral girdle, connecting the arm to the trunk.
- Femur: The thigh bone, which is part of the lower limb.
- Scaphoid: One of the carpal bones in the wrist, part of the upper limb.
The rib, on the other hand, is part of the axial skeleton, not the appendicular skeleton. The axial skeleton includes the bones of the head, neck, and trunk, specifically:
- Skull: Protects the brain and forms the face.
- Vertebral column (spine): Protects the spinal cord and supports the head and trunk.
- Ribs: 12 pairs of ribs that form the rib cage, protecting the heart and lungs.
- Sternum (breastbone): Located at the front of the rib cage.
The axial skeleton provides central support and protection for the brain, spinal cord, and thoracic organs. In contrast, the appendicular skeleton facilitates movement and supports the attachment of limbs to the trunk of the body.
Therefore, among the options provided, the rib is not part of the appendicular skeleton but rather belongs to the axial skeleton.