Bone Tissue And Its Microscopic Structure Flashcards
What are the organic extracellular components of bone tissue and what % do they comprise of bone matrix
33% of bone matrix is organic
Collagen (protein)
Ground substance (proteoglycans)
What is the function of the organic component of the bone extracellular matrix
To resist tension
What are the inorganic components of the extracellular matrix, and what % do they make
67% of extracellular matrix is inorganic
Hydroxyapatite + other calcium mineral
What is the function of the inorganic component of the extracellular bone matrix
To resist compression / make bone hard
What are the 4 cells involved in bone
Osteogenic cells
Osteoblasts
Osteocytes
Osteoclasts
What is bone homeostasis
The balance of bone destruction and formation that results in net bone mass staying the same
What are the functions of the 4 bone cells
Osteogenic cells - stem cells that produce osteoblasts
Osteoblasts - makers (produce new bone matrix)
Osteocytes - maintainers and communicators (recycle proteins + minerals from matrix, control osteoblast/clast activity)
Osteoclasts - destroyers (remove bone matrix)
Outline the similarities and the differences in the structure of compact and cancellous bone
Made of same things (ECM + cells), but structured differently
Compact bone = osteon structure
Cancellous bone = trabecular structure
What are the holes for blood supply in compact bone called
Foramina
What are osteons
Longitudinal units within compact bone that provide a pathway for nutrients to get to cells in the ECM
What components make up an osteon
Central canal - contains blood vessels and nerves
Lamellae - series of cylinders formed of ECM around central canal
Lacunae - lakes for osteocytes
Canaliculi - channels for nutrients through ECM
How do Lamallae contribute to shape of osteon and strength of bone
Shape of multiple cylinders of lamallae around central canal form cylindrical shape of osteon
Collagen fibres in ECM within lamallae resist forces
What are interstitial lamallae
Are irregularly shaped and fill spaces between osteons
What are circumferential lamallae
Layers of bone matrix that perimeter the bone
Outline the composition/structure of cancellous bone
Trabeculae - struts of lamalla bone
Marrow fills cavities between trabeculae
Osteocytes housed in lacuna in between lamellae/on surface
