Exam 2 Skeletal system part 2 Flashcards
Matrix of bone tissue is made up of:
Fibers & ground substance
Fibers of bone tissue are made up of;
Type 1 collagen fibers, which provide strength to resist tensile forces
Ground substance for bone tissue is made up of _______ component and an _______ component
Organic & inorganic compound
Organic component of the ground substance for bone tissue is made up of:
- Proteoglycans
- Chondroitan sulfate, keratan sulfate & hylaluronic
acid
- Chondroitan sulfate, keratan sulfate & hylaluronic
- Glycoproteins- esp. osteocetin and osteoclacin
Inorganic component for ground substance for bone tissue is made up of:
Hydroxyapatite, a mineral composite, which provides strength to resist compressive forces
What are the different types of bone cells:
Osteoprogenitor cells
Osteoblast
Osteocytes
Osteoclast
Give rise to osteoblasts
- Located in the cellular layer of the periosteum and in the endosteum
Osteoprogenitor cells
- lay down new bone tissue
- Located w/in the central & perforating canals of osteons & w/in the periosteum & endosteum
Osteoblasts
Originate from ostoprogenitor cells
Osteoblast
- Former osteoblasts
- Located w/in the lacunae of the osteons of compact bone & bony struts of spongy bone
Osteocytes
Maintain surrounding bone tissue & regulate mineral content
Osteocytes
- Bone destroying cells
- Cells are large & multinucleated, originating from the fusion of several monocytes
Osteoclasts
Secrete acid
Osteoclast
_______ &______ are active during growth and during repair
Osteoblast & osteoclast
What are the types of bone tissue:
Primary & secondary bone tissue
AKA woven bone tissue “immature”
Primary bone tissue
- Develops first, during fetal development
- Also associated w/ repair of fractures
Primary bone tissue
- Collagen fibers are randomly arranged
- Mineral content is lower
- Contains more osteocytes than mature bone tissue
Primary bone tissue
AKA lamellar bone
Secondary bone tissue
Compact bone outer layer of densely packed bone tissue, composed of osteons, Circumferential lamellae, and interstitial lamellae
Secondary bone tissue
Osteons consist of:
Lamellae Central canal (osteonic or Haversian) Lacunae Canaliculi Perforating canals (communicating, Volkmann's)
Concentric layers of bony connective tissue; w/in each layer, the collagen fibers are oriented at right angles to the fibers in the adjacent layers
Lamellae
Contains vascular structures & nerves
Central canal (osteonic, Haversian)
Holes found b/t lamellae
Lacunae
Passageways connecting lacunae to each other & to the central canal
Canaluculi
Connecting central canals to each other
Perforating canals ( Communicating or Volkmann’s)
Multiple layers of mineralized matrix
Circumferential lamellae
Located immediately deep to the periosteum
External circumferential lamellae
Located at the perimeter of the medullary cavity
Inner circumferential lamellae
Layers of mineralized matrix, lying b/t & around osteons; the remains of partially destroyed osteons
Interstitial lamellae
- Found in the interior of a bone
- lattice/network of bony bars & struts, each consisting of just a few concentric layers of bony connective tissue
Spongy bone
Very thin layer of modified compact bone, lacking the extensive vascular channels
Subchondral bone
Found underlying articular cartilage, making up the articular surface
Subchondral bone
Wolff’s Law
A bone remodels it’s shape according to the way force is transmitted through it.
