Which of the following does the skeletal system include?

The skeletal system is primarily composed of bones and cartilage, which serve as the foundational support structure of the human body. Bones provide rigidity, shape, and protection for vital organs, while cartilage serves as a flexible connective tissue that cushions joints, supports various structures, and helps in the growth of bones during development.

While muscles play a crucial role in movement and are closely associated with the skeletal system, they are not part of the skeletal system itself. Similarly, nerves and the brain are components of the nervous system and do not belong to the skeletal framework. Ligaments, although important for connecting bones to one another at joints, are not classified as part of the skeletal system directly but rather as connective tissues that support the skeletal structure.