Skeletal Tissue Flashcards
Name the 4 principle types of tissue in MSK?
epithelial
connective
muscle
nervous
Name 4 types of connective tissue
bone
articular cartilage
tendon
ligament
Which tissue is the most abundant in the body?
connective tissue
What is remarkable of connective tissues?
their ability to withstand repeated loading over multiple years
Name the 4 types of bones
long
short
flat
irregular
What are bone cells called?
osteocytes
What is the non-cellular organic component of bone made from?
strong collagen fibres in a jelly-like matrix called ground substance
Can collagen fibres be stretched?
no - but they are flexible
What is the inorganic component of bone made from?
calcium phosphate crystals deposited within the matrix
What substance gives bone its characteristic hardness and rigidity?
calcium phosphate crystals
What are the two types of bone tissue called?
compact (cortical)
cancellous (trabecular)
How does the quantity of compact bone vary between different areas of bones?
areas of high stress have a higher density of compact bone i.e. femoral shaft
How do cells in cancellous bone align themselves?
in line with directions that will best support the loadings
what is the basic structural unit of compact bone?
Haversian System
What is the basic structural component of cancellous bone?
Trabecula
Describe a Haversian System
They are arranged longitudinally in columns of around 200 micrometers in diameter.
in these units, the bone tissue is arranged in layers called lamellae forming concentric rings around a central canal - the Haversian canal.
This canal contains blood vessels and nerve fibres
Between the lamellae there are small cavities called lacunae that connect osteocytes.
Each osteocyte is links to others and the Haversian canal via cannaliculi - along which nutrients are carried.
Collagen fibres connect layers of lamellae.
Each haversian system is surrounded by ground substance - the weakest part of a bones microstructure.
Describe the structure of cancellous bone
a latticework of branching sheets and columns. Trabeculae are similar to Haversian systems except they do not contain Haversian canals. Haversian canals are not needed in cancellous bone as blood vessels pass through the marrow filled spaces between trabeculae, supplying nutrients to osteocytes through the canaliculi
Why does cancellous bone not need Haversian canals?
Blood vessels pass directly through the marrow filled spaces between trabeculae and supply osteocytes with nutrients via canaliculi
What happens to an object in tension?
it is being stretched like a rope
What happens to an object in compression?
a load is acting to compress the material