Skeletal System Flashcards
Appendicular skeleton
Limbs and girdles –> pectoral and pelvic
Axial skeleton
skull, thoracic cage
Long bone
limbs, medullary cavity, bone marrow
flat bone
thin, curve, compact bone and spongey bone
irregular bone
complex shapes, protection
short bone
cuboidal. wrists and foot
Ligaments connect what?
bone to bone
Tendons connect what?
muscles to bone
Function of skeletal system
protection, mobility, hemopoiesis, storage
composition of bone
1/3 organic, 2/3 inorganic
osteoprogenitor cells (mesenchymal stem cells)
bone membranes
osteoblasts
secrete osteoid matrix. deposition
osteocyte
mature cells. housed in extracellular matrix, found in bone tissue, bone matrix
osteoclasts
bone marrow, osteoclast precursor cells fuse –>osteoclast. huge and multinucleated. breakdown bone + reabsorption: organic and breakdown matrix inorganic.
organic
collagen. proteolytic enzymes.
inorganic
hydroxyapatite crystals. HCL
osteoclast precursor
RANK L/ RANK = prod on development + activation of osteoclast
compact bone
solid, heavy, outside
spongy bone
lighter “spaces”, bone marrow
bone deposition
osteoid (collagen)(osteoblast), calcification (osteocyte)
epiphyseal plate
growth plate. when closes forms epiphyseal line.
epiphyseal line
indicates mature bone
chondrocytes
mature cartilage cells maintains matrix
chondroblasts
immature cartilage cells secretes matrix
hyaline cartilage
no edosteum. missing source of cells
appositional growth
adding to outside (perichondrium)
Interstitial growth
inside
Ossification
process of laying down new bone via osteoblasts
intramembranous ossification
mesenchymal membrane (fibrous mat) vascularized –> flat bone.
mesenchymal cells become osteoprogenitor cells–> osteoblasts which secrete osteoid
endochondral
cartilage model which is transformed into bone –> long bone
resorption
tearing down bone matrix via osteoclasts
sex hormones
stimulates growth. the end of the beginning. esp. plate closing.
thyroid hormone (T3/T4)
critical for formations of growth hormone (GH). basal metabolic rate
zone of resting cartilage
mature cartilage that secures epiphysis to epiphyseal plate
zone of proliferation
chondrocytes–>rapid cell division–>flattened lacunae
zone of hypertrophy
chondrocytes stop dividing+begin hypertrophy–>walls of lacunae thin
zone of calcification
minerals deposited between lacunae killing chondrocytes
zone of ossification
lacunae walls break down, capillaries + osteoprogenites cells enter –> new bone matrix deposited on calcified cartilage matrix
calcitriol
works with parathyroid hormone.
calcitriol is trying to help out
wolffs law
bones respond to stress form accommodate for stress
fracture
simple or compound (breaks thru skin).
hematoma, biological splint, bony callus, remodeling