Lecture 5 Flashcards
What is a young cell?
Osteoblast
Is there elastic in bone?
only INSIDE bone
What are the 2x components of Connective Tissue?
Cells and ECM
What are the 5x components of ECM?
Fibres Matrix Glycoproteins Tissue Fluid Hydroxyapatite
What colour does Cancellous bone stain?
dark purple
What colour does bone marrow stain?
light purple
What are features of bones of the vertebral bodies?
Fine webs of bone
Preferential alignment upwards - indirection of head
Small shafts running sideways, creating a network
Periosteum fibrous tissue on outside
Periosteum
Peri- = outside
osteum = osteogenic properties
Thicker and more fibrous
contains OSteoblasts
Cancellous bone
Trabeculae smallest element
Trabeculae surrounded by bone marrow
Osteocytes in lacunae
What do histological sections of lacunae look like?
often empty
as the cells have fallen out
Endosteum
Thinner and less collagen fibre
More in adult bone
Cells dont do much
Compact bone
markedly thicker
Osteons not located near surface - as blood supply is sourced from Peri and endosteum
finger like process
What layers (collective name) contain osteoblasts?
Osteogenic layers
-both periosteum and endosteum
What sound can you hear when you pull of periosteum?
cracking
fibres running at 90degrees breaking
-cannot pull endosteum off as is too thin
Where are the 2x types of osteoblast growth?
- Osteoblasts Closest to bone, surrounds itself with matrix, incorporating itself in bone and becoming part of new bone by secreting hydroxiapatite and collagen themselves
- Maintain and Remains part of the osteogenic layer
When has an osteoblast completely transitioned to become a mature cell osteocyte?
Once it has matrix hydroxyapatite and collagen surrounding it Completely
Collagen fibrils in histology slide
large numbers in matrix
Produced and secreted by osteoblasts
Cut in cross section (transversely) are coming out of the page - therefore appear to be dots
What is the blotches of dark staining material in a bone histology slide?
dark staining material
crystal
seeds into collagen fibres
What are the features of bone?
Bone is good under tension, compression and torsion
Strong
Lightweight
Dynamic-remodel
What does hydroxyapatite allow resistance to?
pressure and torsion
What is the relative amount of PG in bone?
Small
as is rigid and isnt depressed
only PG is Decorin which allows for alignment of colagen
What are glycoproteins?
small molecules that help bind other matrix molecules together
Osteonectin
