skeletal system Flashcards
functions of the skeletal system
- support
- protection
- leverage/movement
- stores minerals & lipids
- hemopoiesis
what is hemopoiesis?
blood cell production
-red bone marrow
where does yellow bone marrow come from?
lipids
Location of yellow bone marrow
limb bones
location of red bone marrow
- axial bones
- hip bones
- proximal end of humerus & femur
classification/categories of bone + examples
- short bone (carpal bone)
- flat bone (parietal bone)
- irregular bone (vertebra)
- sutural bones
- long bones (humerus)
- sesamoid bones
parts of a long bone
proximal epiphysis metaphysis diaphysis metaphysis distal epiphysis
spongy bone
compact bone
marrow cavity
what part of a long bone contains red bone marrow?
spongy bone (proximal epiphysis)
what part of the long bone contains yellow bone marrow in adults?
medullary cavity in diaphysis
what is articular cartilage?
- cartilage on spots of bone that articulate
- slick & white
- integrated w/ bone (two types of tissue integrated together)
comparison between flat and long bones
flat bone
- compact bone - outside rim
- spongy bone - all inside under compact
long bone
- compact bone - outside
- spongy bone - epiphysis’s
how do adult & child bones differ?
- more cartilage
- epiphyseal plate (growth plate) (childs)
- epiphyseal line (adult)
What is the epiphyseal plate?
- growth plate
- sliver of cartilage
- cellular growth of cells in plate cause growth of bones
epiphyseal line
-epiphyseal plate becomes bone (cells stop growing)
what is achondroplasia?
-spontaneous or inherited genetic abnormality on chromosome #4
What is affected by achondroplasia?
- epiphyseal plate growth in long bones
- short appendages
bone = connective tissue called…
osseous tissue
extracellular matrix =
ground substance + protein fibers + inorganic salts
osseous tissue consists of
- extracellular matrix
- bone-specific cells
1/3 bone mass is…
organic material
- cells
- protein fibers (collagen)
- ground substance (semisolid mix of non-fibrous proteins)
2/3 bone mass is…
inorganic material
-primarily calcium salts
bone matrix consists of?
- ground substance
- protein fibers - collagen
- inorganic material
what is the “mineral component” of bone?
inorganic material
what is the ground substance made of?
- glycosaminoglycans (chondroitin sulfate)
- osteocalcin
- osteonectin
what is osteocalin?
calcium binding protein
what is osteonectin?
anchors bone minerals to collagen
osteoid is made up by what organic items?
- ground substance
- glycosaminoglycans
- osteocalcin
- osteonectin
- protein fibers (collagen)
what is the main protein fiber in bone?
collagen
what inorganic materials are in the bone matrix?
- calcium salts (mostly)
- ca++ phosphate
- hydroxyapatite
what is hydroxyapatite?
calcium phosphate & calcium hydroxide combined
what does hydroxyapatite make?
crystals
what are the crystals from hydroxyapatite made with?
- calcium
- O2
- phosphorus
what happens with the crystals from hydroxyapatite?
-deposited around protein fibers
what is crucial for bone strength?
organic & inorganic components of bone
what happens to bone without minerals?
-becomes rubbery
what happens to bone without collagen?
- becomes brittle
- shatters easy
what are the types of bone cells?
- osteocytes
- osteoblasts
- osteoclasts
- osteoprogenitors
what are osteocytes? What do they do?
- mature bone cells
- maintain bone matrix
what do osteoblasts do?
-add to/build new bone matrix during growth & remodeling
what do osteoclasts do?
-remove/tear down bone matrix during growth & remodeling
what do osteoprogenitors do?
-maintain osteoblast population
what is the arrangement of materials used to make a whole bone?
- periosteum
- endosteum
- osteons
- trabeculae
what is periosteum?
-2-layered tissue that covers the outside surface of a whole bone
what are the two tissues in periosteum?
- dense connective tissue proper (outer layer)
- epithelial tissue (inside layer)
what is endosteum?
-type of epithelial tissue that covers the inside surface (lining f marrow cavity) of a whole bone
is the fibrous layer of the periosteum the inner our outer layer?
outer
is the cellular layer of the periosteum the inner our outer layer?
inner
what are osteons?
circular, repeating unit of compact bone
what are trabeculae?
spongy (cancellous) bone arrangement in a whole bone
what is the compact (dense) bone arrangement in a whole bone?
osteons (Haversian systems)
what is the function of the central canal within the osteons?
allows passageway through bone for veins, artey, nerves
what are concentric lamellae?
- rings of the osteons
- where veins, arteries, & nerves run through bone
what are lacunae?
spaces where octeocytes (bone cells) are located
what are perforating canals?
canals that run horizontal between central canal to connect veins, nerves, & arteries to one another within osteons of bone
what gives compressive strength?
circular arrangment (concentric lamellae) of solidified osteoid
what to collagen fiber components do?
add flexibility
what is canaliculi
passageway through solid matter so octeocytes can extend out and communicate & pass resources to one another
does spongy bone have osteons
no
what is trabecula?
- formed by matrix in spongy bone
- like honeycomb
- random directions
how much skeletal mass is recycled pr year?
about 1/5
what factors affect rate of build-up/breakdown of bones?
- exercise
- hormones
- diet
- aging
what hormone affect the build-up/breakdown of bones?
- estrogen/testosterone
- growth hormone
- thyroid hormone
- calcitonin/ parathyroid hormones
what in diet affect the build-up/breakdown of bones?
- vitamin d
- vitamin c
what is vitamin D needed for in bones?
-calcium absorption
what is vitamin C needed for in bones?
-collagen formation
what is osteoporosis?
- “porous bone”
- not normal
what happens with osteoporosis?
- loose bone mass in spongy bone
- loose strength of bone
- body begins compress & change orientation of vertebral column
- breaking hips easier
what causes osteoporosis?
- hereditary
- age
- malnutrition
what stimulates osteoblasts?
- exercise
- weight bearing
what is osteopenia?
- loosing small amounts of bone mass
- normal
