tulang

Tulang, in Indonesian and Malay, refers to bone, the rigid structures that form the vertebrate skeleton. In humans, the adult skeleton generally contains about 206 bones, arranged to provide support, protect organs, enable movement, and serve as a reservoir for minerals. Bone tissue also houses bone marrow, where blood cells are produced during development and throughout life.

Bone tissue comprises compact bone (cortical) and trabecular bone (spongy). Cells include osteoblasts, which form new bone; osteocytes, which maintain the matrix; and osteoclasts, which resorb bone during remodeling. The outer surface is covered by the periosteum, while the inner lining is the endosteum. Red marrow generates blood cells; yellow marrow stores fat in the medullary cavity.

Growth and development occur through ossification. Intramembranous ossification forms many flat bones, while endochondral ossification replaces cartilage with bone in most long bones. Long bones lengthen at the growth plates (epiphyseal plates) during childhood and adolescence; after maturity, remodeling renews bone and helps regulate calcium and phosphate balance.

Bones are categorized by shape as long, short, flat, irregular, and sesamoid, and by location into the axial and appendicular skeleton. Joints and cartilage enable flexible movement while cushioning loads. Common health issues include fractures from injury, osteoporosis, osteoarthritis, and bone infections such as osteomyelitis. Adequate intake of calcium and vitamin D, physical activity, and avoiding smoking support bone health.