Skeletal system Flashcards
what is the function of long bones
movement
what is the function of short bones
support
what is the function of flat bones
protection
how to describe sesamoid bones
seed like/ small and round
how to describe irregular bones
complex shape
where are sutural bones located
in skull
what type of bone is at the ends of bones
trabecular
what type of bone is in the middle of bones
compact
is compact bone or trabecular bone more porous
trabecular
what is the wider end of a long bone called
epiphysis
what is the tubular shaft of a long bone called
diaphysis
what is the part of the long bone that connects the epiphysis and dialysis
metaphysis
where is the epiphyseal plate located
metaphysis
what does the epiphysis contain
red bone marrow
what does the diaphysis contain
yellow bone marrow (adipose)
what is the epiphyseal plate
growing plate
what is the growing plate made up of
hyaline cartilage
what is the structural unit of compact bone
osteon
what are the rings in osteons
lamallae
where are osteocytes located
lacunae
what are the branches in lacunae called
canaliculi (river canals)
what do canaliculi do
transport nutrients and communicate
what are the 4 ways osteocytes communicate
focal adhesion, gap junctions, cytoskeletons, ion channels
what is the outer layer of compact bone called
periosteum
what are the 2 layers of the periosteum
fibrous and cellular
what are the 3 cells found in the periosteum
osteoblasts, fibroblasts, skeletal stem cells
where do tendons and ligaments attach
periosteum
what is the main purpose of spongy bone
provides structure
how is the web in spongy bone characterized
it’s not random
what is the inner layer of compact bone called
endosteum
what does the endosteum line
medullary cavity
what is the medullary cavity
hollow space in bones
how are osteocytes formed
osteogenic cell –> osteoblasts –> osteocytes
what causes osteogenic cells to form
increase in mitotic activity
what is the matrix that surrounds osteoblasts and makes them turn into osteocytes
collagen and calcium matrix
what 2 things form osteoclasts
monocytes and macrophages
what makes long bones
endochondrial ossification
what do mesenchymal cells turn into in endochondrial ossification
chondrocytes
what covers cartilage in endochondrial ossification
perichondrium
what happens as the matrix increases in endochondrial ossification
chondrocytes grow
what happens to the matrix eventually in endochondrial ossification
it calcifies and dies
what happens once blood vessels invade the space in endochondrial ossification
they carry osteogenic cells
what happens when chondrocytes grow at the ends of bones
epiphysis is formed
what CT forms bones in intramembranous ossification
mesenchymal CT
what forms when osteoblasts cluster in intramembranous ossification
ossification center
what happens to osteoblasts when matrix calcifies in intramembranous ossification
they’re trapped
what happens when osteoblasts become trapped in intramembranous ossification
they turn into osteocytes
what does new osteoblasts on the surface create in intramembranous ossification
periosteum layer
what is formed when trabecular bone crowds the blood vessels
RBC are formed
what happens in secondary ossification
epiphysis grows bone
where does the growth of long bone occur
metaphysis
what is formed that causes the epiphyseal side to grow
cartilage
what is formed that causes the diaphysial side to grow
bone
what is the reserve zone
small chondrocytes that don’t participate in growth
what does the reserve zone secure
epiphysis
what kind of growth stops in adulthood
longitudinal
what do chondrocytes do to bone growth in adulthood
cease proliferation
what does bone replace during bone growth in adulthood
cartilage
how do bones grow in diameter via osteoclasts
osteoclasts reabsorb old bone
how do bones grow in diameter via osteoblasts
osteoblasts produce new tissue beneath the periosteum
what is the master regulator in bone growth
osteocytes
out of RANK, RANKL, OPG, SOST what do osteocytes make
RANKL, OPG, SOST
what is RANK
receptor on osteoclast
what does RANK bind to
RANKL
what causes bone formation in the RANK system
RANKL and OPG
what does SOST do
inhibits bone formation or reabsorption
what is osteoporosis
low bone mass
what is the proliferative zone
stacks of chondrocytes
how are chondrocytes made in proliferative zone
mitosis
what happens to the chondrocytes in the zone of maturation and hypertrophy
they get older and larger
what happens to chondrocytes in zone of calcified matrix
they die
what happens to capillaries and osteoblasts in zone of calcified matrix
they penetrate and secrete bone tissue
what does the zone of ossification connect
epiphyseal plate to diaphysis
what causes bone to grow in zone of ossification
osseous tissue is added to diaphysis
