L4 Part 2 Flashcards
Long bones develop according to ______ ossification. this means these bones started off as a ______ model
what type of cartilage was this model?
endochondral
cartilage
hyaline
What 2 areas remain untouched at the end of endochondral ossification (in long bones)
articular cartilage(hyaline) at the joint (ball) epiphysial plate
In interstitial bone growth, Name the 4 functionally different zones that arrange into a pattern that allows fast and efficient growth
- resting cartilage
- proliferating cartilage
- hypertrophic cartilage
- calcified/ossified cartilage
In interstitial bone growth, how are the 4 fictionally different zones arranged on either side of the long bone?
the calcified cartilage is always closest to the diaphysis/medullary cavity (they reverse order depending what side of the long bone they are on)
In interstitial bone growth, in one of the 4 fictionally different zones; Resting cartilage zone: what does this zone do?
chondrocytes anchor epiphyseal plate to epiphysis of bone
In interstitial bone growth, in one of the 4 fictionally different zones; Proliferating zone: what does this zone do?
chondrocytes divide, secreting ECM PUSHING epiphysis from diaphysis
In interstitial bone growth, in one of the 4 fictionally different zones; Hypertrophic Zone: What does this zone do?
cartilage is pushed further away from the epiphysis and they hypertrophy and die
In interstitial bone growth, in one of the 4 fictionally different zones; which zone has bone cells?
the calcified/ossification zone
In interstitial bone growth, in one of the 4 zones is the calcification and ossification zone. in this zone,
bone forms in place of _____
_______ dissolve calcified cartilage and ________ secrete bone matrix. this becomes the _______
cartilage
osteoclasts, osteoblasts
diaphysis
The epiphyseal plate remains the same width during interstitial growth, how?
because of the hypertrophic zones eating away the unnecessary tissue above and below the plate as it moves farther away from the medullary cavity elongating the bone.
Appositional Growth is responsible for the growth of length or width? What types of cells are involved?
Width
only bone cells
interstitial is growth from _____ occurring from the ______ ______ and is cartilage with the exception of the _____ ______.
within, growth plates
calcified ossification zone
once the bone has been formed after interstitial growth and (this phase is complete by _____) However once the bone is developed where does cartilage remain? it remains at the ____ ____ and the ______
(birth)
articular cartilage
epiphyseal plate
Appositional Growth has 4 steps what are they?
Osteoblasts secrete bone matrix
ridges fold around the blood vessel
concentric lamellae (fills in the tunnel) formed by matrix secreting osteoblasts
circumferential lamella is formed by osteoblasts deep into the periosteum
the central canals in bone are formed around _____ _____ ____.
preexisting blood vessels
what is a series of concentric lamellae called?
an osteon
Bone remodeling: Resorption….. is accomplished by _____. Osteoclasts ‘ruffled- hair like’ borders function is _____ a seal on ____ and _____ surfaces. Then lysosomal enzymes _____ fibers acids and calc salts into soluble forms.
dissolved matrix transported via _______ across osteoclast.
substances _____ from the interstitual fluid into _____ _____
osteoclasts ______ while ________ enter
osteoclasts
creating a seal on endosteal and periosteal surfaces
digest
transcytosis
diffuse, blood capillaries
leave while osteoblasts enter
where does bone reabsorption take place on the bone?
endosteal and periosteal surfaces
what is transcytosis?
both endo and exocytosis across a cell
bone deposit is accomplished by _______.
The bone deposit has 2 steps what are they?
where and why does this process occur
osteoblasts
osteoblasts move into repair the resorbed area
the new matrix is secreted by osteoblasts and matures for 1 week before it calcifies.
Occurs where injured bone is or where more strength is needed
bone remodeling requires both ____ _____ and bone _____.
bone resorption and bone deposit
Factors Affecting bone tissue _____ -and _______
mineral and vitamins
important Hormones in infancy and childhood that affect bone tissue are ___ and ____ which control epiphyseal plate activity.
Thyroid hormones modulate the activity of ____ to ensure ____ _____ as it grows by stimulating osteoblasts.
insulin increases synthesis of _______ ______ (______)
GH and IGFs
GH, proper proportions
bone protiens (collagen)
During puberty the hormones that take over are
they increase _____- activity and promote adolescent growth spurts.
cause masculinization and feminization of ___ ____ ___ ___ ___.
testosterones and estrogens
osteoblast
specific parts of the skeleton
