Histology - Hard Connective Tissue Flashcards
what are the fuctions of bones?
mechanical functions, haematopoesis, calcium homeostasis
what is haematopoesis?
formation of blood components
what is the principle of section modulus?
increasing the cross section of an object but with the same amount of material (making it hollow) increases bending resistance
what does using composite materials do?
combines strengths in compression and tension resistance –> makes an overall stronger structure
what is strain relief?
when two different materials connect to each other, there is stess concentrated at the discontinuity. spreading out the material so the shift from one material to the next is gradual spreads out the stress and makes a stronger connection
what is the point to making bones hollow?
increases section modulus, reduces energy needed to make and maintain bone, reduce the amount of energy needed to hold bones up by muscle
what is corticol bone?
solid bone on the outer surface of the bone
what is trabecular bone?
the spongy bone inside of the corticol bone
what is the main organic material in bone?
collagen (type I)
what is the main inorganic material in bone?
hydroxyapatite
what does collagen do in bone?
resists tensile forces
what does hydroxyapatite do in bone?
resists compressive forces
what are osteocytes?
cells that maintain bone tissue
what are osteoblasts?
cells that create new bone
what are osteoclasts?
cells that get rid of bone
what is Howship’s lacunus?
the space around an osteoclast
what is the arrow pointing to?
osteoclast
what is apposition?
bone added on top of existing bone
how does bone grow?
apposition
where does bone growth occur?
on growth plates near the ends of bone
what does removing calcium from bone do?
removes resistance to compression –> bone becomes very rubbery and soft
what is woven bone?
created when osteoblasts make bone rapidly
no real orientation to material/fibers
what type of bone are antlers made out of? why?
woven bone
they grow super fast
what type of bone is this?
woven bone
what is lamellar bone?
created when osteoblasts make bone slowly and put materials in a proper orientation
stronger
what type of bone is this?
lamellar/Haversian bone
what is intramembranous bone?
bone formed directly in a membrane
what is the advantage to intramembranous bone? what is the disadvantage?
quicker because it starts in multiple places and comes together
cannot load bear while bone is growing
what is this picture showing?
intramembranous bone formation
what is endochondral bone?
bone that forms from a cartilaginous precursor
what type of cartilage is involved in endochondral bone?
hyaline cartilage
what is this photo showing? what are the letters pointing to?
endochondral bone formation
A: proliferation zone (bone growth)
B: maturation and hypertrophy (normal cells)
C: calcified matrix (cell death)
D: zone of ossification (metaphysis)
what is another name for growth plates?
epiphyseal cartilages
how does primary bone modelling work?
- bone formation at the surface of bone produces ridges that paralell a blood vessel
- ridges enlarge and create a deep pocket
- the ridges meet and fuse, trapping the vessel inside the bone
what is this photo showing? what is the black arrow pointing to? what is structure A?
mature lamellar bone
arrow: blood vessel in central canal
A: osteocyte
what is the Bone Multicellular Unit (BMU)? what is the function of it?
unit with osteoclasts at the front and osteoblasts at the back
resorb and lay down new bone
what is a Haversian canal?
hole in the middle of an osteon where the BMU passed through
what is an osteon?
how bone is laid down by BMUs
concentric circles with a hole in the middle
what is Volkmann’s canal?
lateral branches of the circulatory system
what is this photo showing? what do the letters mean?
remodelled bone
A: osteon
B: Volkmann’s canal
C: Haversian canal
what is periosteum?
connective tissue around the outside of bones
what is endosteum?
connective tissue lining Haversian canals
label this photo
A: endosteum
B: periosteum
what is bone marrow?
gelatinous tissue that fills trabecular bone
what are the types of bone marrow?
red and yellow
what does red marrow do?
create RBCs, WBCs, platelets, endothelium, mesenchyme
what does yellow marrow do?
create cartilage, fat, bone
what do stromal cells do?
fix matrices
what does red marrow contain?
hematopoeitic stem cells, mesenchymal stem cells, endothelial stem cells, stromal/dendridic cells, megakaryocytes
what does yellow marrow contain?
stromal cells, adipocytes
what are trabeculae?
projections of bone inside trabecular bone that hold things together
what is this picture showing? label it
A: megakaryocyte
B: adipocyte
C: haematopoeitic and meylopoeitic cells
what is this photo showing? label it
A: bone
B: tendon
C: calcified fibrocartilage
D: fibrocartilage
E: mineralization front
showing tendon insertion into bone
