The physical foundation of the body composed of 206 bones is the

• A. Muscular system
• B. Endocrine system
• C. Skeletal system
• D. Integumentary system

Answer: (C)

The body’s rigid framework is provided by the skeleton, the physical foundation built from 206 bones in an adult. Bones form the structural support that gives the body its shape, supports posture, and protects vital organs (for example, the skull shields the brain and the rib cage guards the heart and lungs). They also serve as attachment points for muscles, so when muscles contract, movement occurs by acting lever-like on the bones. Beyond support and movement, bones store minerals such as calcium and phosphorus and house bone marrow for blood cell production, underscoring how the skeletal system is foundational to structure, protection, and metabolic functions. The other systems don’t establish the body’s rigid framework: the muscular system enables movement but relies on the skeleton for attachment and leverage; the endocrine system regulates processes through hormones; and the integumentary system covers and protects the body but doesn’t provide the internal framework.