general osteology Flashcards
what makes up the skeletal system
bones, cartilages, joints
what is the diff btw osteology and arthrology
osteo;study of b
arthrology; study of joints
what are the classes of bones
long, short, flat and irregular
what is the name for a living skeleton (human) and a non-living skeleton (insects)
living; endoskeleton
non-living ; exoskeleton
what are the functions of b (6)
support protection acts as a lever (w m.) for mvt storage/release area for minerals blood cell formation (RBCs) triglyceride storage (Yellow b. marrow)
what are the types of ossification
endochondral and intramembranous
what is endochondral ossification
bone forms by replacement of hyaline cartilage (long b. of the extremities)
what is intramembranous ossification
forms directly in the matrix by increasing growth of collagenous fibers (flat b. of the skull and face)
what is bone tissue
a complex and dynamic living tissue that is constantly remodeling and is several tissues working together; osseous, caritlage, dense ct, epi, adipose and nervous
what is the precursor cell to bone and what does it turn into and so on
osteoprogenitor cell becomes an osteoblast (forms b. extracellular matrix) and then an osteocyte (maintains b. tissue)
what is an osteoclasts from white blood cell lineage
functions in resorption,
the breakdown of b. and extracellular matrix
what are the general features of b
diaphysis epiphysis metaphyses (epiphyseal plate) articular cartilage periosteum medullary cavity endosteum
what is observed at the surface of a bone, but can extend deeper, makes up most of the diaphysis and looks dense to the naked eye but is quite porous microscopically
compact b
t/f is compact b resistant to stresses but not weight and movement bearing mvt (
false they are resistant to it (offers protection and support)
what are the parts of compact b. tissue (9)
- osteons (structural unit),
- osteonic canal,
- concentric lamellae (rings that make up osteons),
- lacunae (space btw lamellae, contain osteocytes),
- canaliculi (canals to join up diff osteocytes),
- interstitial lamellae (fills in gaps),
- interosteonic canals (inbtw osteons),
- circumferential lamellae (goes around entire circumference of shaft)
- sharpey’s fibers (anchored to the b)
what are the 2 layers of periosteum
fibrous (outter layer)
osteogenic (inner layer)
what are called fibrous mem that surround complete bone and covers diaphysis but not bone ends at articular cartilage
periosteum
what is another name for trabecular bone
cancellous or spongy bone
what kind of bone is located in the interior of the bone, and doesn’t contain osteons
spongy bone
what is contained inside the trabeculae of spongy bone and how would you describe it
- concentric lamellae, osteocytes, lacunae, canaliculi
- lamellae arranged in an irregular pattern of thin columns
what are spaces in btw the trabeculae filled with in spongy bone
red bone marrow (blood cell production) or yellow bone marrow (adipose tissue)
periosteal arteries enter ___ thru ___ and supply ____ and outer part of ___ b.
diaphysis, interosteonic canals, periosteum, compact
nutrient arteries enter near center of ___ via oblique angled hole called ___ foramen with path always __ from the dominant ___ end of the b
diaphysis nutrient
away growth
finish phrase; __ to the ___ and __ the ___
go to the elbow and flee the knee
metaphyseal a. arise from __ around associated ___
arteries joint
epiphyseal a. arise from arteries around associated ___
joint
which a. supplies the medullary cavity
nutrient a.
what are the 4 stages of b. formation
- initial formation in embryo and fetus
- general growth thru infancy, childhood and early adulthood
- bone remodeling thru life
- repair (from fx) thru life
what is b. initially from and where is it found
initially from mesenchyme and its found in the embryo
what is intramembranous ossification (where is it found and what are the steps)
found in flat b. (skull), most facial b. and mandible
mesenchyme to b
what is endochondral ossification (what bones are formed w this and what are the steps)
most other bones formed this way including all long bones
mesenchyme to cartilage model to b.
what are the defined steps of intramembranous ossi (4)
1-developpement of the ossification center
2-calcification
3-formation of trabeculae
4-development of the periosteum
describe developpement of the ossification center of intramembranous ossi
osteoblasts secret organic extracellular matrix
describe calcification of intramembranous ossi
calcium and other mineral salts are deposited and extracellular matrix calcifies
describe fomration of trabeculae of intramembranous ossi
extracellular matrix develops into trabeculae that fuse to form spongy b.
describe developpement of the periosteum of intramembranous ossi
mesenchyme at the periphery of the b. develops into the periosteum
what are the 6 steps of endochondral ossi
1-development of the cartilage model
2-growth of the cartilage model
3-development of the primary ossification center
4-development of the medullary cavity
5-development of the secondary ossification center
6-formation of articular cartilage and the epiphyseal growth plate
describe development of the cartilage model in endochondral ossi
mesenchymal cells develop into chondroblasts which form the cartilage model
describe growth of the cartilage model in endochondral ossi
growth occurs by cell division of chondrocytes
describe development of the primary ossification center in endochondral ossi
in this region of the diaphysis, b. tissue has replaced most of the cartilage
describe development of the medullary cavity in endochondral ossi
b. breakdown by osteoclasts forms the medullary cavity
describe development of the secondary ossification center in endochondral ossi
these occur in the epiphyses of the b
describe formation of articular cartilage and the epiphyseal growth plate in endochondral ossi
both structures consist of hyaline cartilage
what is the zone of reserve/resting cartilage of growth in length
closes to the epiphysis, consists of small scattered chondrocytes
what is the zone of proliferating cartilage of growth in length
larger chondrocytes undergo interstitial growth, divide and secrete extracellular matrix
what is the zone of hypertrophic cartilage of growth in length
large maturing chondrocytes
what is the zone of calcified cartilage of growth in length
- dead chondrocytes bc extracellular matrix has calcified
- osteoclasts dissolve calcified cartilage, then osteoblasts and capillaries invade area
- osteoblasts lay down b. extracellular matrix, process of endochondral ossification, new diaphysis formed as a result
what are the 4 steps of b. growth in thickness
1-ridges in periosteum create groove for periosteal blood vessel
2-periosteal ridges fuse, forming an endosteum-lined tunnel
3-osteoblasts in endosteum build new concentric lamellae inward toward center of tunnel, forming a new osteon
4-b. grows outwards as osteoblasts in periosteum build new circumferential lamellae. Osteon formation repeats as new periosteal ridges fold over blood vessels
final shape of cartilage model is determined by
gravitational forces (pressure epiphyses) functional forces (traction epiphyses)
