Bone Flashcards
What is bone composed of?
Similar to dentin (but not anatomically)
HA overlaid on a collagen I scaffold
-67% - Inorgo - HA
-33% - Orgo
—28% - Collagen
—5% - Noncollagenous proteins
What are the non-collagenous proteins in bone?
Bone sialoprotein (BSP)
Osteopontin (OP)
Osteocalcin (OC)
Osteonectin (ON)
Matrix extracellular phophoglycoprotein
What 3 cell types are in bone?
Osteoclasts
Osteoblasts
Osteocytes
What are 4 physiological roles of bone?
Structural
Ca2+ homeostasis
Reservoir for growth factors in tissue repair
Hematopoietic and mesenchymal progenitor cell populations in marrow
Calcitonin does what?
Removes Ca2+ from blood and put it into bone
PTH does what?
Takes Ca2+ from bone and puts it into blood
What is the macrostructure of bone?
Outer layer of dense, compact (cortical) bone, with an inner cavity
Inner cavity with marrow, red or yellow, and cancellous trabecular bone
HIGHLY VASCULAR
T/F - Cholera diarrhea disturbs Ca2+, drops significantly, and is pretty much plasma diarrhea.
TRUE
What are the 3 organizational units of compact bone?
Circumferential - Outer ring of bone tissue
Concentric (osteonic) lamellae - Intact osteons
Interstitial lamellae - Fill space b/t concentric lamellae, former concentric lamellae
What is the basic functional unit of compact bone?
The osteoblasts
Look at slide 6. Picture of bone with labels
Do it
An osteon is formed from?
Concentric lamellae
Basically concentric rings of bone, built around a canal housing a capillary (Haversian Canals)
What links Haversian canals?
Volkmann canals
What heals faster, bone or cartilage?
Bone
-It is much, much more vascular than cartilage
Where there is blood, there is healing
Where is cancellous bone found?
Spongy bone
End of long bones, in apposition to jts and is associated w/ the marrow spaces
What does cancellous bone do?
Provides structure support for marrow tissues, highly vascular
Site of blood cell production, supports mesenchymal and hematopoietic progenitor cell populations
Layers of bone from outside in.
Periosteum
Outer Circumferential lamellae
Osteonic lamellae
Haversian canals
Inner circumferential lamellae
Endosteum
Marrow cavity with trabecular bone
How is the periosteum connected to the outer surface of bone?
SHARPEY’S FIBERS
Outer fibrous layer and inner layer in apposition to the bone surface
Which layer of the periosteum is highly cellular and vascularized, outer or inner?
Inner layer
What is endosteum?
Loose connective tissue covering the inner surface of both cancellous and compact bone
Separates the marrow from the bone
T/F - Volkmann’s canals connect osteons, while osteons are built around Haversian canals.
TRUE
What are osteoblasts?
Bone forming cells with MESENCHYMAL origin
What are osteocytes?
Bone cells
- Encapsulated osteoblasts
- Housed in osseous lacunae