Lecture 7 Flashcards
What is the periosterum?
A fibrous membrane that coats the outer surface of the bone
What is the endosteum?
Endosteum lines the medullary (marrow) cavity. Lines inside of bone
Where is compact bone found?
Diaphysis/Shaft
Where is cancellulous bone found?
Epiphysis/ends of bone
Compact bone contains cylinder shaped structures called?
Osteons
What runs through the middle of osteons and provides passage of blood vessels?
Central canal
Within each osteon there are layers of calcified matrix called?
Lamellae
Spaces in the lamellae are called:
lacuna- which contain osteocytes
Lacuna are connected by small canals called? These canals allow?
Canaliculi - allow communication between bone cells.
Cancellulous bone structure:
criss-crossing struts/branches called trabeculae which align themselves towards stresses - load bearing
Function of cancellulous bone:
to resist compression - act as shock absorbers
Function of compact bone:
to resist tension/stretch. Found where strength and load bearing needed. Dense & solid compared to cancellulous bone.
What are bones made out of:
Connective tissue which is made out of cells(osteocytes) & ECM
What are the two components that make up ECM?
33% Organic & 67% Inorganic
What is the Organic component of ECM made out of?
Collagen fibres & proteoglycans (ground substance)
What is the function of the organic ECM?
Resists stretch/tension e.g tendons, ligaments & bone all contain extensive collagen in their ECM as they need to resist stretch
What is the function of the inorganic ECM?
Provides rigidity and resistance to compression
Hardness - resists compression & tension
What is the inorganic component of ECM made out of?
Mineral salts (hydroxyaptile)
What is the function of compact bone?
Resists tension - provides strength
What is the function of cancellous bone?
Resists compression
