Bones Flashcards
What are the 4 main functions of bone?
Weight bearing, protection, mineral storage and blood formation
Name the membrane covering the outside of bones.
periosteum
Name the membrane covering the bone marrow segment of bones.
endosteum
What is bone composed of?
Osteocytes, osteoblasts, osteoclasts.
What makes a bone stiff but not brittle?
collagen 1
What is the structure of cortical bone?
Osteons with Haversian canals which have blood vessels going through too vascularise
What is the structure of spongy bone?
Made of trabeculae with bone marrow surrounding the gaps
what are other names for spongy bone?
Cancellous or Trabecular
What is the name of the canals running through a bone vertically and horizontally?
Haversion canal and Volkmann’s canal
What is the lamellae (matrix) composed of?
Collagen 1, hydroxyapatite crystals (between collagen fibres) and water
What is the name of long bone formation
Endochondral ossification
What is the name of flat bone formation
Intramembranous ossification
What happens during long bone formation?
Cartilage is converted to bone through ossification centres. Eventually this takes over the entire cartilage. Leaves 2 epiphysial growth plates.
What is the name of the cartilage plates left behind in long bone formation?
Epiphysial growth plates
What are osteoprogenitor cells?
Stem cells found in the periosteum and endosteum which can mature into osteoblasts
What are mesenchymal cells?
Stem cells which divide into osteoprogenitor cells, then osteoblasts
About Osteoclasts
Osteoclasts - large, multinuceated, created from hematopoeitic stem cells, break down bone by releasing acid from its ruffled border
How are osteocytes formed?
Osteoblasts wrap themselves in osteoid and become osteocytes
What is an osteoid
Bone marrow without any minerals
What cell initiates the calcification of osteoid
Osteoblasts
About Osteoblasts
Differentiated by mesenchymal and osteoprogenitor cells. Build up bone by producing osteoids and calcifying it.
Name of communication network between osteocytes
Canaliculi
What are 3 regions on long bone and where are they found?
Metaphysis (where epiphyseal growth plate is found), epiphysis (end), Diaphesis (main midsection)
Condyle vs Epicondyle?
Condyle is smooth and round, binding bone to bone. Epicondyle binds bone to muscle, tendon or ligaments
What is interstitial growth?
Growth occurring from the epiphyseal growth plates
Which growth represents an increase in width? (what causes this?)
Appositional growth (from periosteum)
What are the two types of bone growth?
Interstitial and apositional
Why do we have sesamoid bones?
Embedded within muscle or tendons, releasing the tension in that area. Important for running
Red bone marrow vs yellow bone marrow
Red bone marrow is present in bones which still produce RBC due to the haemoglobin. Yellow is inactive and yellow due to adipocytes
