BONE MIDTERM Flashcards
maintains bone tissue
Osteocyte
forms bone matrix
Osteoblast
resorbs bone
Osteoclast
termed as fibrous because it is
composed of type I collagen fibers, fibroblasts, and also
there are blood vessels in this layer
outer fibrous layer
contains the
osteoblast, as well as the osteoprogenitor cells
inner/cellular/osteogenic layer
are located between the internal circumferential lamellae
and the external circumferential lamellae.
Osteons
The boundary between
each osteon is the
cement line.
_______ is a refractile line of
modified bone matrix. Anastomosis between central canals is called
______
cement line and the perforating or Volkmann canal.
central canal of an osteon that allows blood vessels,
lymphatic vessel nerves to travel along the osteon.
Haversian canal
transverse branch of a haversian canal that interconnects
haversian canals with each other.
Volkmann’s canal
cancellous or
trabecular bone
SPONGY BONE
made up of osteons
COMPACT BONE
made up of trabeculae
SPONGY BONE
contains yellow bone
marrow
COMPACT BONE
contains red bone
marrow
SPONGY BONE
forms major parts of the
long bones such as
arms and legs
COMPACT BONE
forms major parts of the
short bones such as
wrists and ankles
SPONGY BONE
acts as a buffer for
compact bones
SPONGY BONE
provides structural
support to the body
COMPACT BONE
cuboidal inner porous,
less dense, osseous
tissue
SPONGY BONE
cylindrical harder outer
layer of the bone
COMPACT BONE
cortical bone
COMPACT BONE
osteoblasts differentiate directly from mesenchyme and
begin secreting osteoid
* mandible, maxilla, clavicle, and flat skull bones are
formed by this process
* fontanelles in newborn skulls represent
intramembranous ossification in progress
INTRAMEMBRANOUS OSSIFICATION
from the Greek word ‘endon’ meaning ____, plus
‘condros’ meaning ______
within and cartilage
typical histology of resting
hyaline cartilage
Zone of reserve cartilage
chondrocytes multiplying and
lining up in rows of small flattened lacunae
Zone of cell proliferation
cessation of mitosis;
enlargement of chondrocytes and thinning of lacuna walls
Zone of cell hypertrophy
temporary calcification of cartilage
matrix between columns or lacunae
Zone of calcification
breakdown of lacuna walls,
leaving open channels; death of chondrocytes; bone
deposition by osteoblasts, forming trabeculae of spongy
bone
Zone of bone deposition
woven bone is then remodeled as ______
lamellar bone
bone tissue first appears
* osteoblasts settle in a layer over the spicules of calcified
cartilage matrix and secrete osteoid which becomes
woven bone
* woven bone is then remodeled as lamellar bone
* bony material is deposited on the plates of calcified
cartilage matrix
ZONE OF OSSIFICATION
chondrocytes about to undergo apoptosis release matrix
vesicles and osteocalcin to begin matrix calcification by
the formation of hydroxyapatite crystals
ZONE OF CALCIFIED CARTILAGE
chondrocytes in lacunae increase in size as a result of
swelling of the nucleus and cytoplasm
* hypertrophy – increase in size of the cells
ZONE OF HYPERTROPHY
cartilage cells divide repeatedly, enlarge and secrete
more type II collagen and proteoglycans
* chondrocytes are organized into columns parallel to the
long axis of the bone
PROLIFERATIVE ZONE
composed of typical hyaline cartilage
* shows chondrocytes in their lacunae distributed
singly or in small groups (isogenous groups)
ZONE OF RESERVE (OR RESTING) CARTILAGE
