Bone cells, cartilage and function Flashcards
What are the functions of bone in the body?
Support and muscle attachment. Houses haematopoiesis (formation of blood cells from stem cells). It is needed for protection and as a reservoir for calcium and phosphate.
What are the percentages of what makes up bone?
25% matrix (90% type 1 collagen, 5% protein, 5% water)
75% minerals (inorganic hydroxyapatite which is calcium-phosphate material)
What happens when you add acid or bleach to bone?
Acid dissolves the minerals and bleach dissolves the minerals
What are the 3 sections of a long bone called and where can you find the growth plate?
Epiphysis (end)
Metaphysis
Diaphysis (centre)
Growth plate in the metaphysis
Name and describe the cells found in bone
Osteoblasts - bone forming cells - cuboidal - sit on bone surface Osteoid - matrix not yet mineralised Osteocytes - formed from osteoblasts - embedded in lacunae - connected via canaliculi Lining Cells - lie on surface Osteoprogenitor cells - osteoblast precursors - found in periosteum - sit above osteoblasts as they are not yet osteoblasts Osteoclasts - only cells in body which degrade bone - sit in holes called Howship/s lacunae - multinucleated
Where is hyaline cartilage, fibrocartilage and elastic cartilage found?
Hyaline = trachea, articular joints, ribs Fibro = intervertebral disc and tendon Elastic = ear, larynx
What does type 1 and type 2 collagen make up?
1 = skin, bone, tendons, dentine 2 = cartilage
What is a proteoglycan?
A glycoprotein which consists of a protein attached to a GAG.
List the differences between bone and cartilage
B = rigid, C = deformable B = impermeable, C = permeable B = 25% matrix, 75% mineral, C = 25% matrix, 75% water B = appositional, C = appositional and interstitial B = vascularised, C = not vascularised
What cells come from mesenchymal stem cells? What cells come from heamatopoietic stem cells?
osteoblasts, osteocytes, lining cells, osteoprogenitor cells, chondrocytes
osteoclasts, monocytes/macrophages
What is the difference between woven and lamellar bone?
Woven = immature bone, fracture healing, irregular collagen fibres, high cellular content, less calcified Lamellar = all mature bone, low cellular content, heavily calcified
How are cortical and trabecular bone arranged?
Where are Haversian systems found?
Cortical - rings
Trabecular - sheets
Cortical bone
What is the function of a Haversian system/osteon?
A system of lamellae containing blood vessels and nerves. Communication between them occurs via osteocytes.
What is the function of a Haversian canal?
Nutrient canals, allowing communication between osteons.
How many lamellae is an osteon limited to and why/
6 lamellae because the nutrients have to pass the whole way via diffusion
