How does the appendicular skeleton differ from the axial skeleton?

The appendicular skeleton comprises the limbs, including the bones of the arms, legs, shoulders, and pelvic girdle. This part of the skeleton is primarily responsible for facilitating movement and locomotion, which is critical for various physical activities such as walking, running, and grasping. The design of the appendicular skeleton allows for a wide range of motion at the joints, highlighting its vital role in movement—in contrast to the axial skeleton that supports the body's structure and protects the brain, spinal cord, and thoracic organs.

When examining the other options, it's clear that they describe characteristics of the axial skeleton rather than the appendicular skeleton's unique features or functions. The skull and spine are integral components of the axial skeleton, and the statement about containing more bones typically refers to the overall number of bones in the entire human skeleton rather than distinguishing between the two. Lastly, while the axial skeleton does play a crucial role in protecting vital organs, such as the heart and lungs, the appendicular skeleton is distinguished by its primary function related to movement, making it essential for the mobility and agility of an organism.