Bone Biology Flashcards
Yellow marrow
Reserve of fat cells in the medullary cavity of tubular bone, surrounded by compact bone.
Red marrow
Blood-forming, hemopoietic tissue that produces red and white blood cells and platelets.
Epiphyses
Ends of long bone, developed from secondary ossification centers.
Diaphysis
Developed from bone’s primary ossification center.
Metaphyses
Expanded, flared ends of shafts.
Periosteum
Thin, outer surface, bone covering tissue that nourishes bone. It coats all bone surfaces not covered by cartilage. (Osteogenic)
Endosteum
An ill-defined and largely cellular membrane that lines the inner surface of bone. (Osteogenic)
Osteogenic (tissue)
Contains bone-forming cells. More numerous and active during youth than adulthood and can deposit bone when the periosteum is traumatize.
Collagen
Protein molecule that intertwines to form elastic fibers in bone and it makes up 90% of bone’s organic content.
Hydroxyapatite
Stiffens collagen of mature bone.
Immature/Coarsely Bundled Bone/Woven Bone
First bone that develops rapidly in prenatal life but is later replaced with mature bone during growth. It characterizes embryonic skeleton, sites of fracture repair, bone rumors, and has higher osteocytes than mature bone.
Mature/Lamellar Bone Tissue
Makes compact and trabecular parts of bone. It has organized structure because of uniform addition of lamellae to bone surfaces during apposition all growth.
Haversian Lamellae
“Trunk” with 4-8 concentric rings.
Haversian System/Osteon
Each “trunk.” Basic structural unit of compact bone. 0.3mm in diameter and 3-5mm in length.
Haversian Canal
Pass through core of osteons and they’re hallow canals where blood, lymph, and nerve fibers pass.
Volkmann’s Canals
Link haversian canals thus creating a network that supplies blood and lymph to the cells of long bones.
Lacunae
Small cavities containing osteocyte found in lamella.
Osteoblasts
Bone-forming cells beneath periosteum, responsible for synthesizing and depositing bone material. They make lot of osteoid.
Osteoid
Uncalcified organic matrix rich in collagen.
Osteocytes
Living bone cell formed when osteoblasts are surrounded by bony matrix. They are located in lacunae and maintain bone tissue.
Osteoclasts
Responsible for the removal of bone tissue.
Compact/Cortical Bone
Solid, dense bone found in the walls of bone shafts and on the external bone surfaces.
Subchondral Bone
Compact bone at joints covered by cartilage. It’s smoother and shinier but doesn’t have haversian systems.
Cancellous/Trabecular/Spongy Bone
Spongy, porous, lightweight, honeycomb structure bone found under protuberances. It attaches to tendons in the vertebral bodies, in the end of long bones, in short bones and sandwiched within flat bones.
