skeletal system Flashcards
functions of the skeletal system
1.) body support
2.) organ protection
3.) body movement
4.) mineral storage
5.) Blood cell production
provides firm yet flexible support to areas
cartilage
by weight, it is i normally about 35% organic and 65% inorganic material
bone matrix
strong bands of fibrous connective tissues that hold bones together
ligaments
inorganic materials in the bone primarily consist of ?
calcium phosphate crystal
organic materials in the bone primarily consist of ?
collagen and proteoglycans
responsible for the major functional characteristics of the bone
collagen and minerals
what are calcium phosphate crystal called
hydroxyapatite
if mineral in the bone is reduced, it results to what?
collagen becomes primary constituent and bone becomes overly flexible
the matrix ground substance consist of molecules called
proteoglycans
three types of bone cells
osteoclast
osteoblast
osteocytes
it means imperfect bone formation, a rare disorder caused by any one of the number of faulty genes that results in too little collagen production.
brittle bone disease/ osteogenesis imperfecta
are bone building cells
osteoblast
cells that have extensive endoplasmic reticulum and numerous ribosomes
osteoblast
osteoblast secrete high concentration of
Ca+ and phosphate ions
acts as templates that stimulate formation and mineralization of the matrix
hydroxyapatite
formation of new bone by osteoblast is called?
ossification
can occur multiple times during life; as a fetus, when growing larger and time in life when fracture is repaired
ossification
osteocytes account how much of the bone cells?
90-95%
osteoblast become what?
osteoclast
osteocytes has a life span of how many years?
up to 25 years
osteocytes cell bodies are housed with the bone matrix in spaces called?
lacunae
osteocyte cell extensions are housed in narrow, long spaces called
canaliculi
are bone destroying cells
osteoclasts
breakdown of bone is called
reabsorption
osteoclast develop from?
red bone marrow cells
osteoclast develop a
ruffled border
a specialized reabsorption of a specific area of the membrane
ruffled border
mature bone is called?
lamellar bone
is a solid, outer layer surrounding each bone
compact bone/CORTICAL BONE
spongy bone consist of interconnecting rods or plates of bone called
trabeculae
osteon is composed of
concentric rings of matrix
the functional unit of compact bone is called
osteon
in cross section, an osteon resembles a circular target
central canal
is the center portion of the bone and is primarily composed of bone tissue
diaphysis
hollow center
medullary cavity
the ends of long bones are called
epiphyses
is a connective tissue membrane covering the outer surface of the bone
periosteum
the end of the long bones that are covered with hyaline membrane is called
articular cartilage
when bone stops growing in length, the epiphyseal plate becomes ossified called
epiphyseal line
is located between the epiphysis and diaphysis
epiphyseal
is the site for blood cell formation
red marrow
is mostly adipose tissue
yellow marrow
is a single cell layer of connective tissue that lines the internal surfaces of cavities within bones
endosteum
bone formation in the fetus follows two processes
1.) intramembranous ossification
2.) endochondral ossification
the locations in the membrane where intramembranous ossification begins is called
center of ossification
soft spots, are the larger, membrane-covered spaces between the developing skulls
fontanels
the formation of cartilage begins at approximately the end of the fourth week of embryonic development
endochondral
a hyaline cartilage model is produced by cells called
chondrocytes
endochondral ossification starts at the
eight week of embryonic development
the osteoblast produce bone on the surface of the cartilage model forming a
bone collar
the chondrocytes in the center of the cartilage model absorb some of the
cartilage matrix and hypertrophy
formation of hydroxyapatite is called
calcified cartilage
forms as osteoblast produce bone on the surface of the calcified cartilage
primary ossification center
are created in the epiphyses by osteoblasts that migrate into the epiphysis
secondary ossification center
the cartilage model is surrounded by
perichondrium
the osteoblasts produce compact bone on the surface of the cartilage model, forming a
bone collar
the chondrocytes initiate in the formation of hydroxyapatite crystals in the cartilage matrix, at this point the cartilage is called
calcified cartilage
the chondrocytes in the center of the cartilage model absorb some of the
cartilage matrix and hypertrophy
forms as osteoblasts produce bone on the surface of the calcified cartilage
primary ossification center
are created in the epiphysis by the osteoclasts that migrate into the epiphysis
secondary ossification center
blood vessels grow into the enlarged lacunae of the calcified cartilage
primary ossification center formation
