Sesh 7: Cartilage And Bone Flashcards
What is periosteum?
Dense, irregular connective tissue that covers the surface of bones.
What type of cartilage is ossified during endochondral ossification, to form most types of bone?
Hyaline cartilage.
Endochondral ossification increases bone ________.
Length.
What type of bone contains trabeculae?
Spongy/cancellous/trabecular bone.
What is intramembranous ossification?
Bone development directly from mesenchymal tissue, giving rise to mostly flat bones.
What is osteoid composed of?
Extracellular matrix + type I collagen
What are the spaces between trabeculae of spongy bone filled with?
Bone marrow
What runs through the centre of an osteon?
Haversian canal containing blood vessels, lymph and nerves.
What are Volkmann’s canals?
Run longitudinally along bone, not surrounded by concentric lamellae. Interconnect Haversian canals, so contain blood and lymph vessels, and nerves.
What are cannaliculi and what are their function?
Cytoplasmic processes of osteocytes that extend to other osteocytes via gap junctions to communicate and pass nutrients, and also connect with the Haversian canal.
How is the structure of spongy bone different to compact bone?
- No volkmann’s or haversian canals (get nutrients from bone marrow)
- Irregular lamellae
What is a cutting cone?
A bone remodelling unit that runs parallel to the orientation of osteons.
Why does bone density decrease with age?
Reduced osteoblast activity…less bone formed, but still being resorbed….imbalance in bone remodelling.
What % of bone is made of calcium hydroxyapatite crystals?
65%
What type of collagen makes up 23% of bone?
Type I