Your skeleton isn't just a passive frame. It's a dynamic system that supports your body, enables movement, and protects vital organs. From storing minerals to producing blood cells, your bones are constantly at work.

Beyond structure, your skeleton is a living tissue. It undergoes continuous remodeling, stores energy, and works with cartilage to provide both strength and flexibility where needed. Your skeleton is truly the backbone of your body's functions.

Functions of the Skeletal System

Functions of skeletal system

• Supports body framework maintains shape and posture (upright stance)
• Anchors soft tissues like muscles, tendons, and ligaments for stability
• Enables movement by acting as levers for muscle attachment at joints allowing range of motion
• Protects vital organs from external damage
  • Cranium encases brain
  • Ribcage shields heart and lungs
  • Vertebral column surrounds spinal cord

Bone storage and production

• Stores essential minerals calcium and phosphorus in hydroxyapatite crystals within bone matrix
• Osteoclasts break down matrix releasing minerals into bloodstream when body needs them
• Osteoblasts incorporate minerals into new bone matrix during formation and remodeling
• Yellow bone marrow stores triglycerides as energy reserve for body
• Red bone marrow produces blood cells through hematopoiesis
  • Hematopoietic stem cells differentiate into red blood cells (erythrocytes), white blood cells (leukocytes), and platelets (thrombocytes)
  • Occurs in medullary cavity of bones like vertebrae, ribs, sternum, pelvis, proximal ends of long bones in adults
• Plays a crucial role in calcium homeostasis by regulating mineral release and storage

Bone structure and remodeling

• Osteocytes, mature bone cells, maintain bone tissue and respond to mechanical stress
• Periosteum, outer layer of bone, contains blood vessels and nerves for bone nourishment
• Endosteum lines inner bone surfaces and contributes to bone remodeling
• Bone undergoes continuous remodeling to repair microdamage and adapt to mechanical forces
• Bone marrow fills the inner cavities, supporting hematopoiesis and fat storage

Bone vs cartilage in skeleton

• Bone is hard mineralized tissue that supports body, protects organs, enables movement, stores minerals/fat, produces blood cells
• Cartilage is flexible resilient connective tissue that cushions joints (articular cartilage), acts as template for bone development (endochondral ossification), maintains shape of structures (nose, ears, trachea)
• Cartilage provides smooth low-friction joint surfaces while bone provides structural support
• During growth, cartilage at epiphyseal plates allows longitudinal bone elongation
• Cartilage persists where flexibility needed (intervertebral discs) and bone dominates where strength and rigidity required (femur)
• Biomechanics of bone and cartilage determine their functional roles in the skeletal system