Fractures
Bone breaks into three or more pieces. Common in older individuals with more brittle bones
Comminuted Fracture
The shaft or long central portion of a long bone. Made mostly of compact bone. Contains the medullary cavity (bone marrow cavity)
Diaphysis
Marrow that produces red blood cells
Red Marrow
The basic structural unit of compact bone. A cylindrical structure that runs parallel to the long axis of the bone. Contains a central canal surrounded by concentric lamellae
Osteon (Haversian System)
What is a blood clot that forms around a bone injury called?
Hematoma
Caused by twisting forces. Bone has a ragged break. Common in sports injuries
Spiral Fracture
The ends of a long bone (proximal and distal)Made mostly of spongy bone surrounded by thin compact bone. Contains red bone marrow in adults (site of blood cell production).
Epiphysis
Marrow that stores fat in long bones.
Yellow Marrow
The central opening in each osteon. Contains blood vessels, nerves, and lymphatic vessels. Supplies nutrients to bone cells
Central Canal (Haversian Canal)
Stage of bone repair where the bony callus is reshaped into normal bone structure. Osteoclasts remove excess bone, and osteoblasts lay down new lamellar (mature) bone. Bone regains its original shape, strength, and internal structure.
Bone Remodeling
Bone is crushed. Common in vertebrae, especially in people with osteoporosis
Compression Fracture
Hollow space in the diaphysis. Contains yellow marrow (fat storage) in adults
Medullary Cavity
Dense and smooth bone tissue. Forms the outer layer of all bones. Provides strength and protection.
Compact Bone (Cortical Bone)
Rings of hard, calcified matrix surrounding the central canal. Provide strength and resilience to bone.
Lamellae
Stage of bone repair where fibroblasts and chondroblasts infiltrate the hematoma. They produce collagen fibers and cartilage, forming a soft callus that bridges the gap between bone ends. Blood vessels begin to regrow in the area (angiogenesis).
Fibrocartilaginous Callus Formation (Soft Callus Phase)
Bone breaks incompletely, like a green twig. One side of the shaft breaks, the other side bends. Common in children.
Greenstick Fracture
Tough outer membrane covering the surface of the bone. Contains blood vessels, nerves, and osteoblasts. Helps in bone growth, repair, and attachment of tendons/ligaments
Periosteum
Porous, lightweight bone with trabeculae (lattice-like structure). Found mostly in epiphyses and short, flat bones. Contains red marrow (produces blood cells)
Spongy Bone (Cancellous Bone)
Mature bone cells located in lacunae. Maintain the bone matrix and signal bone remodeling. Connected to each other via canaliculi
Osteocytes
Stage of bone repair where osteoblasts (bone-forming cells) replace the soft callus with woven bone, creating a hard bony callus. This new bone is immature but strong enough to unite the broken bone ends.
Bony Callus Formation (Hard Callus Phase)
Epiphysis separates from the diaphysis at the epiphyseal plate. Can affect growth in children and adolescents.
Epiphyseal Fracture
Smooth hyaline cartilage covering the epiphyses where bones meet. Reduces friction and absorbs shock in joints
Articular Cartilage
Thin membrane lining the medullary cavity. Contains bone-forming cells (osteoblasts and osteoclasts)
Endosteum
Perpendicular to central canals. Connect central canals of different osteons. Allow blood vessels and nerves to travel between osteons and bone surface
Perforating Canals (Volkmann’s Canals)
What is a skeleton’s least favorite room in the house?
The Living Room