w7 bone Flashcards
what is the shaft of long bones
diaphysis
what is the articular end of long bones
epiphysis
what is the growth region between diaphysis and epiphysis of long bones
epiphyseal plate/disc
what is the transitional area between diaphysis and epiphyseal plate o flong bones
metaphysis
bone made of what type collagen fibers
type 1 collagen fibers
how much of the bone is inorganic component and what is a main component
about 65% of dry weight of bone
hydroxyapatite
where are osteogenic (osteoprogenitor) cells located
found in the deepest layer of periosteum, adjacent to the endosteum
osteogenic cells derived from what
mesenchyme
osteogenic cells undergo cell division to give rise to what
osteoblast
osteoblast found where
on periosteal and endosteal surfaces of bone
how to osteoblast communicate
by gap junctions
role of osteoblasts
SECRETE THE BONE MATRIX, SIGNALING
when does an osteoblast become an osteocyte
when an osteoblast surrounds itself w matrix
where are osteocytes located
in LACUNA
osteocytes processes of adjacent cells connected by what
gap junctions
role of osteocytes
maintain BONE MATRIX, MECHANOTRANSDUCTION
how do osteoclasts attach to bone, and what does that surround
attach to bone by SEALING ZONE,
which surrounds a RUFFLED BORDER
role of osteoclasts
BONE RESORPTION, SIGNALING
compact bone tissue located where and laid down where
located in peripherla part of bone and laid down in OSTEONS (harversian system)
lamellae 3 types and location
concentric (haversian) - form the osteon itself
interstitial - between osteons
circumferential - around outside and inside of bone
what does the periosteum do
nourish bone tissue, provide supply of new osteoblasts for appositional bone growth or repair
what does the endosteum do
covers internal surface of bone (trabeculae, walls of marrow cavity)
spongy bone (cancellous or trabecular bone) formed from what
interconnecting trabecular (tissue elemnt in the form of a small beam, strut, or rod)
where is the spongy bone located
marrow spaces between trabeculae
periosteum of the skull is called what
pericranium
bones of the skull have 2 external bony tables separated by spongy bone called what
diploic bone
what is marrow
cellular material occuyping spaces inside bone
what does red marrow consist of
developing blood cells
contains reticular cells and reticular fibers
has abudnat sinusoids
what does yellow marrow consist of
adipose tissue found within medullary cavity
which marrow type replaces the other as people age
yellow replaces red marrow
what does parathyroid hormone do
stimulate bone resorption, thus elevating blood calcium levels
what does calcitonin do and what gland is it secreted by
inhibits osteoclast activity, and promotes urinary excretion of calcium and phosphate
secreted by thyroid gland
what does sex steroids do
promote bone growth during adolescence and prevent bone loss in adulthood
