Chapter 8 Flashcards
This cell synthesizes organic components of the matrix
Osteoblasts
What are the cells of bone
Osteocytes, osteoblasts, osteoclasts
Cells that are multinucleated, giant cells involved in the resorption and remodeling of bone tissue
Osteoclasts
____________ is on the internal surface and the _______________ is on external surface both surround the bone cavity
Endosteum, Periosteum
A layer of new ( but not calcified) material called __________ between the osteoblast layer and the preexisting bone surface
Osteoid
A small, vitamin K- dependent polypeptide ________ which together with various glycoproteins binds Calcium ions and raises their concentration locally
Osteocalcin
These are rich Alkaline Phosphatase and other enzymes whose activity raises the local concentration of Phosphate ions
Matrix vesicles
____________ are enclosed singly within the lacunae that are regularly spaced throughout the mineralized matrix
Osteocytes
In transition from osteoblasts to osteocytes the cells extend many long ___________ processes, which also become surrounded by calcifying matrix.
Dendritic
Osteoclasts lie within these enzymatic ally etched depressions or activities I the matrix known as______________ or ________________
Resorption cavities, Howship Lacunae
There are two polypeptides produced by osteoblasts : Macrophage Colony Stimulating Factor or ___________ and the receptor activator of nuclear factor kB ligand called ___________
M-CSF, RANKL
Osteoblasts are activated by the _______________ hormone which slows Osteoblasts to release M-CSF and RANKL
Para-thyroid
A Bone specific multi adhesive glycoprotein
Osteonectin
Bundles of periosteal collagen fibers penetrate the bone matrix binding the periosteum to bone.
Perforating /Sharpey fibers
Mesenchymal stem cells found cellular layer in the inner region of the periosteum , has the potential to proliferate and differentiate into osteoblasts
Osteoprogenitor cells
Internally the very small_______ covers small trabeculae of bony matrix that project into the marrow cavities also contains osteoprogenitor cells, osteoblasts, and bone lining cells
Endosteum
Represents 80% of the total bone mass
Compact ( cortical) bone
Numerous interconnecting cavities , makes up about 20% of total bone mass
Cancellous ( trabecular or spongy) bone
The bulbous ends of long bones, are composed of spongy bone covered by a thin layer of compact bone
Epiphyses
The cylindrical part which is almost totally composed of compact bone, with a thin region of spongy bone
Diaphysis
The flat bones that form the calvaria ( skullcap) have two layers of compact bone called
Plates
Plates are separated by a thicker layer of spongy bone called
Diploe
There are two types of organization on bone tissue
Lamellar and woven
Found In most adults, and is in compact or cancellous, characterized by multiple layers of this calcified matrix, 3-7 micrometers thick
Lamellar bone
Refers to the complex of concentric lamellae surrounding a small central canal that contains blood vessels, nerves, loose connective tissue, and endosteum
An Osteon
What is another name for an Osteon?
Haversian system
The outer boundary of each Osteon is a more collagen rich layer called the
Cement line
The central canals communicate with the marrow cavity and the periosteum and with through transverse
Perforating canals
What is another name for perforating canals
Volkmann canals
Irregularly shaped groups of parallel lamellae remained from osteons partially destroyed by osteoclasts during growth and remodeling of bone
Interstitial lamellae
Lamellae located around the marrow cavity
Inner circumferential
Lamellae that are located immediately beneath the periosteum
External circumferential lamellae
Is continuous throughout life and involves a process of bone resorption and bone formation
Bone remodeling