Skeleton, Locomotor system : bone and cartilage

🟠 Classification of Bones
🔹 By Development:
Cartilaginous: from cartilage (limb bones).
Membranous: from membrane (skull bones).
🔹 By Structure:
Compact bone: dense & solid.
Cancellous (spongy): trabeculae, at bone ends.
🔹 By Shape:
Long – femur
Short – carpal
Flat – scapula
Irregular – vertebra
Sesamoid – patella
Pneumatic – maxilla
📌 Divisions of Skeleton
🔹 Axial Skeleton
Skull: cranium + facial bones.
Vertebral column: 33 vertebrae
C7, T12, L5, S5 (fused), Coccyx 4 (fused)
Thoracic cage: sternum + 12 ribs
True (7), False (3), Floating (2)
🔹 Appendicular Skeleton
Upper limb: scapula, clavicle, humerus, ulna, radius, carpals, metacarpals, phalanges.
Lower limb: hip bone, femur, patella, tibia, fibula, tarsals, metatarsals, phalanges.
🚨 Clinical Importance
Growth plate injuries → affect bone length.
Osteoporosis → reduced bone density, fractures.
Knowledge of bone classification aids in identifying fracture types and treatment planning.