Bone

Bone is a rigid, mineralized connective tissue that forms the skeleton. It supports and protects the body, stores minerals, houses marrow, and provides leverage for movement.

Osteoblast: A bone-forming cell that produces the organic matrix of bone and helps regulate its mineralization. Osteoblasts build new bone matrix during growth and repair.
Bone remodeling: The ongoing replacement of old bone tissue with new tissue through coordinated resorption and formation. Remodeling renews bone while adjusting its structure to changing demands.
Osteoporosis: A skeletal disorder characterized by reduced bone strength and increased susceptibility to fractures. Osteoporosis shows how loss of bone mass and structure weakens the skeleton.
Cartilage: A resilient connective tissue that supports structures and cushions joints without the mineralized rigidity of bone. Cartilage bends and cushions where bone provides rigid support.
Vertebrate: An animal belonging to the group characterized by a backbone or its embryonic precursor. Bone is a defining skeletal material in many vertebrate lineages.
Osteoclast: A large cell that breaks down bone tissue by dissolving mineral and digesting matrix. Osteoclasts remove old or damaged bone as part of remodeling.
Wolff's law: The principle that bone architecture adapts over time to the mechanical loads placed upon it. Repeated loading helps determine where bone is reinforced or resorbed.
Osteogenesis imperfecta: A genetic disorder, usually involving type I collagen, that causes fragile bones and other connective-tissue features. This disorder reveals how defective matrix proteins compromise bone strength.
Compact bone: Dense bone tissue organized into tightly packed osteons, forming much of the outer layer of bones. Its close-packed structure contrasts with the open spaces of cancellous bone.
Cartilaginous fish: Jawed vertebrates such as sharks and rays whose adult skeletons are primarily cartilage. Their skeletons show that vertebrate support does not require a bony internal skeleton.

Linked from 24 pages