A&P Ch 7 Flashcards
bone tissue
functions of the skeleton
support, protection, movement, electrolyte balance, acid-base balance, blood formation
bones
bone tissue=osseous tissue=calcified CT. bones are made up of many tissues. osseous, nervous, fibrous ct and blood
shapes of bones
long, short, flat, irregular
long bone
femur, ulna, radius
short bone
carpals, tarsals
flat bone
scapula, sternum
irregular bone
vertebrae
features of bones
compact, spongy, articular, diaphysis, epiphysis, marrow cavity, periosteum, endosteum, epiphyseal plate, epiphyseal line
compact bone features
outer layers of all bones, diaphysis of long bones
spongy bone features
heads of long bones, middle of all others(diploe)
articular features
covers joint surfaces, hyaline cartilage
diaphysis features
shaft of a long bone
epiphyses features
end of a long bone
marrow cavity features
also called the medullary cavity. contains bone marrow
periosteum features
has outer fibrous layer composed of collagen fibres. fibres may be continuous and bind to other bones via ligaments and muscles via tendons. has inner osteogenic layer composed of osteogenic cells and osteoblasts
endosteum features
lines the medullary cavity. contains osteogenic cells and osteoblasts
epiphysieal plate features
found in growing bones. separates marrow spaces btwn epiphysis and diaphysis of long bone. children
epiphyseal line features
found in adult long bones. remnant of the epiphyseal plate
osteogenic cells
(stem cells) origin=fibroblasts. location=edosteum lining medullary, trabeculae, central canals. periosteum lining the outside. lining the trabeculae throughout spongy bone. function=mitosis, some stay behind, some become osteoblasts
osteoblasts
(build bones). origin= osteogenic cells. function= build bone, secrete collagen, alkaline phosphatase (raises pH so crystals form)
osteocytes
mature osteocytes. origin=osteoblasts. location=surrounded by bone matrix. function=stress sensors. absorb nutrients, direct bone remodelling.
osteoclasts
stem cells fuse together. origin=blood cells. location= same as osteogenic cells and osteoblasts. function= reabsorption of bone. secrete acid phosphatase to break down collagen, secrete HCl to break down Ca2+ crystals
matrix
organic=provides flexibility, composed of collagen. inorganic=provides strength, hydroxyapatite. makes bones stuff.
compact bone
osteon is the structural unit. collagen fibres are in alternating orientations to increase strength. fibres are organized in corkscrew pattern along length of bone. highly vascularized, nutrients flow from nutrient foramina through perforating canals to central canals and then from osteocyte to osteocyte via canaliculi
spongy bone
found in epiphysis of long bones and in middle of all other bones. is a lattice of trabeculae with marrow in the spaces in btwn trabeculae. trabeculae are arranged along stress lines. strong but light. osteogenic cells and osteoblasts line the trabeculae
bone marrow
found in medullary cavity and epiphyses of long bones and around trabeculae of spongy bone.
red marrow
hemopoietic= produces all the blood cells. found in all spongy bone of children. found in axial skeletons & pevis, heads of femur, humerus of adults
yellow marrow
produces blood cells only in chronic anemia
endochondral ossification=bone elongation
most bones are produced this way. embryonic tissue(mesenchyme)->hyaline cartilage model-> bone.
metaphysis
the transition between cartilage and bone at each end of the bone. occurs in fetus and until a person reaches final height.
appositional growth
widening of the bone, occurs at the periosteum
wolfs law of bone
bone adapts to stresses applied to it. strength of bone depends on use.
