IGNIS | Page 7

Cranium Parts of Bone s periosteum bone marrow Ribs compact bone Vertebrae Pelvis cancellous (spongy) bone Carpal bones Metacarpal bones Phalanges At birth, every long bone is made of three individual bones separated by cartilage. Each end of the bone is called an epiphysis and the middle bone is called a diaphysis. These bones grow towards each other and eventually fuse. Patella Calcaneus (heel bone) Talus There are several layers that make up a bone. The outer layer of periosteum is dense, connective tissue. Inside the periosteum is the compact bone which is one of the hardest materials in the body. It is made of a matrix of hard mineral salts, reinforced with tough collagen fibres. Beneath the compact bones is the spongy bone. This is a network in the form of a honeycomb. The bone tissue grows in columns called trabeculae. There are spaces for bone marrow in between these columns. Long bones also have a hollow medullary cavity in the middle of the diaphysis where red bone marrow is contained in childhood, turning into yellow bone marrow in maturity. IGNIS 7