chapter 8 part 1 Flashcards
what type of tissue is bone?
connective tissue
what makes bone hard?
mineralizeed matrix
what type of homeostasis is in bone system?
stable levels of calcium
what is the main protein of bone amtrix?
collagen
what percent is ground substance in the ecm?
10%
non collagenous proteins
-proteoglycans
-multiadhesive glycoproteins
-k dependant proteins
-growth factors and cytokines
proteoglycans
core protein with glycosaminoglycans
-FOR BONE STRENGTH
-bind growth factors and PREVENT MINERALIZATION
Multiadhesive proteins
-ATTACH BONE CELLS AND COLLAGEN TO MINERALIZED GROUND SUBSTANCE
osteoprotin
mutliadhesive protein
-the glue btwn crystals and collagen
k dependent proteins
-protein s= remove cells after apoptosis
growth factors and cytokines
-regulatory proteins and insulin like growth factors
-tumor necrosis factor
-bone morphogenic proteins
bone morphogenic protein
differentiate mesenchyme into osteoblasts
-it is osteogenic protein
what connects the lacunae?
a network of canaliculi
canaliculi
a tunnel that goes through the matrix and lets cell processed of neighboring cells happen
4 bone cell types
-osteoprogenitor cells
-osteoblasts
-bone lining cells
-osteoclasts
osteoproginator cells
from mesenchymal cells and become osteoblasts
osteoblasts
secrete the ecm
once the cell has been surrounded with the matrix it becomes the osteocyte
bone lining cells
on the bone surface WHERE THERE IS NO ACTIVE GROWTH
osteoclasts
bone removal/ remodeling
which of the bone cells are phagocytic?
osteoblast
synovial
free moving joint
-hyaline cart.
medullary cavitiy
bone marrow
what covers the surface of bone?
periosteum (dense c.t.)
-less when there is no active growth
-collagen fibers are parallel to the bone
sharpeys fibers
colalgen fibers that extend from the periosteum into the ecm of the bone
articular surface
where two bones connect
THERE IS NO PERICHONDRIUM
Endosteum
one cell thick
-they are osteoproginator cells that became osteoblasts
-endosteal cells
-also bone linning cells
marrow
-has reticular fibers
-RED MARROW DOES NOT GROW WITH BONE
-Fat= yellow marrow (will increase with age)
what type of marrow increases with age?
yellow marrow
what do mature osteocytes have?
concentric llamellae
-they surround the central canal
nutrient foramine
-the opening in the bone hwere the b.v. reaches the marrow
-in diaphysis and epiphysis
-metaphyseal arteries bring the blood
why is immature bone nonllamelar?
-because of collagen arrangement
mature bone stains best with?
eosin
immature bone stains best with?
hematoxolyn
what trigers differentiation in an osteoproginator cell?
core binding factor alpha
-the osteoprog are made inside and out of the cell and have light staining
what is the protein in the matrix of osteoblasts?
osteoid
what junctions do osteoblasts use?
gap junctions
what does the mature bone cell have that the immature does not?
a matrix to enclose it
-matrix is secreted by osteoblasts
osteocyte can do what to the matrix?
degrade it through osteolysis
what causes repairs?
osteoblasts
when are canaliculi visible?
-visible in ground stains
-NOT VISIBLE IN H AND E
3 osteocyte stages
-quiscent
-formative
-resoptive
quiescent osteocyte
-small golgi
-mature calcified matrix
formative
-larger golgi
-osteoid
resoptive
-more lysosome and golgi and er
-IT IS THE PERICELLULAR SPACE AND HAS NO COLLAGEN
osteolysis
breaks down the MMP (matrix mellaproteinases)
bone lining cells are
-former osteoblasts that cover non remodeling bone
-flat layer of cells
-external= periosteal
-internal= endosteal
-gap junctions
-regulate calcium and phosphate entering and leaving the bone
osteoclasts
-multinucleated
-has reportion bay
-DO NOT come from osteoblasts
-gran and monocyte cell lineages
-2 trans factors
-3 regions
osteoclast regions
-ruffle border
-clear zones
-basolateral region
ruffled border
-direct contact w bone
-microvilli for exocytosis
-slight stain
-nuclei far from bone
clear
-perimeter of cytoplasm
-a compartment of the ruffled border
-where resorption and degradation happen
actin fillaments
basolateral
-exocytosis of digested material
-where transport vesicles from ruffle fuse and release content
how to osteoclast resorb bone?
release proteina nd lysosomal hydrolases into ecm
-after they suicide
what are most vesicles in osteoclasts?
lysosomes
