Skeletal system Flashcards
are bones living tissue?
Yes
Are bones connective tissue?
yes
what are the functions of the skeletal system?
- Structure/Support
- Protection
- Movement (body levers)
- Mineral storehouse( for Calcium, Phosphate)/ Calcium Homeostasis
- Blood cell production (hematopoiesis)
example of a long bone example of short bone example of flat example of irregular example of sesamoid
- femur
- carpal bones in hands, tarsals in feet
- sternum
- vertebrae
- patella
What are the cells of interest in terms of bone/skeletal system?
Osteogenic cell ==>osteoblasts–>osteocyte–> osteoclasts
What is an osteoblast? What is the general role of an osteoblast?
“Bone-builders”–> DEPOSITION (via secreting collagen fibers and other organic components)
- Growth
- Repair
- Remodeling
- -> form the bone extracellular matrix
What is an Osteocyte? And what is the general role of an osteocyte?
- A mature bone cell,
- Maintenance/ maintains the bone tissue
What is an Osteoclast? General Role?
“Carve out bone” –> Osteoclasts: Resorption(breakdown of bone extracellular matrix)
- Unloading
- Repair
- Remodeling
Can osteons be found in trabeculae ?
No! only in compact bone
Inner surface of a bone called?
Endosteum (also contains osteoblasts, clasts, and cytes)
Outer surface of a bone called?
Periosteum
what is bone made of??
- Bone cells : cytes, blasts, clasts, osteogenic
2. ECM: Organic and Inorganic
What are the components of Organic Bone ECM? (healthy)
30%
- Collagen ( type 1 )
- Gel
What are the components of Inorganic Bone ECM? (healthy)
70%
Hydroxyapatite –> mineralized form of calcium and phosphate
list different types of mechanical loading of a bone
- Compression
- Tension
- Shear
- Torsion
- Bending
Define Bone Strength (in regards to load-deformation graph)
-Load at the failure point
Define Bone Stiffness/Rigidity
- Slope
- Load required to deform a bone at a given amount
Define Toughness
- Area under the load-deformation curve
- Energy required to yield or fracture the bone
Brittle Bone composition?
70% inorganic, 30% organic
what is compact bone tissue STRUCTURE consist of?
Structural units of osteons (haversian systems)
where are osteocytes located?
Within the concentric lamellae of an osteon
what are lacunae?
Lacunae is the space between an osteocyte and lamellae
How do osteocytes communicate and receive and transport nutrients?
Via the cannaliculi which run horizontally connecting the osteocytes towards each other and throughout the bone
another name for perforating canals?
Volksmann’s canals
volksmann canals structure?
They run perpendicular to the central canals, and connect each canal towards the outer surface of the compact bone (periosteum)
Purpose of volkmann’s canals?
Used as means for blood vessels, lymph vessels, and nerves to supply the compact bone.
what are sharpey’s fibers made of and function?
They are thick bunds of collagen, and supply the outside of the bone (periosteum) with nutrients to assist in bone repair/remodeling.
another name for spongy bone tissue?
trabeculae
Do trabeculae have osteons? Why or why not?
NO, they are not nearly as dense as compact bone already have a lot of space.
Is spongy bone most of the time within a bone? or outside of a bone?
Interior of a bone.
How can diet affect bone composition (in context of organic)
Protein and Vitamin C help create more collagen
How can diet affect bone composition (inorganically)
Lack of Calcium and Vitamin D –> affects the mineral composition and can weaken of soften bones ( ie rickets and osteomalacia)
Why is spongy bone so important??
Red bone marrow
Why is red bone marrow so important?
Blood cell production ! (hematopoesis)
Why is bone considered a living tissue?
Because it is adaptive: they undergo
- growth
- repair (macro/microdamage)
- Remodeling
What do you mean by remodeling?
Bone remodeling is formation of new bone tissue and the breakdown of old bone tissue
Explain the 4 cell types of bone tissue
Osteogenic cells –> progenitor bone cells that develop into osteoblasts
- osteoblasts - build new bone/ forms the bone ECM via secreting collagen and entrapping themselves within a matrix to mature into osteocytes
- osteocytes - maintain the bone tissue, theyre the main cells in bone tissue, regulate exchange of nutrient and waste of bone tissue with blood
- osteoclasts -resorption ie. carve out/break down bone (via lysozomal enzymes), releasing Ca+ as a product.
What and where is the yield point on Load-Deformation graph?
Yield point is the pt at the end of the elastic, and start of plastic region. It is the amount of load in which a bone will begin to fracture permanently and no longer elastic
What and where is the failure point on Load-Deformation graph?
The failure pt is at the end of the plastic region: and it signifies the point at which actually breaks/fracture
How do I find the maximum deformation of a bone?
It is the number drawn vertically from the failure point.
