chapter 6 Flashcards
functions of skeletal system
support, storage of minerals, storage of lipids, blood cell production, protection, and motion
diaphysis
shaft of long bone
epiphysis
ends of long bone
periosteum
covers outer surface of bone
layers of the periosteum
osteogenic- cells for bone formation and break down
fibrous- dense irregular CT, attachment of tendons
endosteum
inner marrow lining
epiphyseal plate
hyaline cartilage until adulthood
articular cartilage
remains on the outer surface of the epiphysis where joint forms
flat bone structure
sandwich of spongy bone, Diploë- layer of spongy bone between compact (hard) bone
bone tissue types
dense matrix-deposits calcium salts, osteocytes within lacunae
canaliculi- small canals for blood vessels, nutrients and waste exchanges
periosteum- covers outer surface of bone, fibrous and inner cellular layers
bone matrix
ground substance of calcium phosphate and calcium carbonate, compression strength, collagen, elastin, flexible strength
types of cells in the bone IN ORDER OF HOW THEY ARE MADE
1 osteoprogenitor cells (osteogenic/preosteoblasts)
2 osteoblasts
3 osteocytes
4 osteoclasts
canals in the bone
haverisan- central, runs vertical, comes out of the osteons
volkmann- perforating, runs horizontal
osteoprogenitor cells
found in endosteum (yellow marrow) and periosteum, comes from mesenchymal cells
osteoblasts
makes the osteoid but not yet calcified form of bone. “pre-bone”
osteocytes
mature bone cells, calcified, arranged in concentric lamellae
osteoclasts
break down of bone, derived from white blood cells called monocytes
circumferential lamellae
lines that make it look like a tree age lines within the trunk along the outer most edge, binds osteons together
osteon
basic unit of compact bone
intersitial lamellae
separates osteons that are present within the bone
structure of spongy bone
no osteons, matrix forms network of trabeculae which have no blood vessels, red bone marrow which has blood vessels, found at epiphysis of long bone and interior of flat bones
structure of compact bone
hard outer surface, composed of osteons, concentric layers of osteocytes, lamellae surround haversian canal
osteogenesis vs ossification
osteogenesis- bone formation
ossification- replacing other tissues with bone
two types of ways that bone can be made
calcification and ossification
two types of ossification
intramembranous and endochondral
intramembranous ossification
start with mesenchymal and fibrous connective tissue, makes flat bone like skull
endochondral ossificaition
ossifies bone that originates in hyaline cartilage *most bones originate as this
epiphyseal plate
made of hyaline cartilage, black line on x-ray
epiphyseal line
when long bone stops growing, epiphyseal cartilage disappears
appositional growth in length
bone is deposited on the DIAPHYSEAL side of the epiphyseal side
appositional grown in width
compact bone thickens and strengthens with layers of circumferential lamellae
most abundant mineral in the body…
calcium!!!!
how is calcium homeostasis maintained?
by calcitonin and parathyroid hormone which control storage, absorption and secretion
PTH increases this activity which increases Ca+ because more bone being broken down to be recycled? but then calcitonin decreases Ca+ levels by decreases the amount of bone broken down by osteoclasts and therefore the amount of bone available
parathyroid hormone
increases Ca+ levels in blood by STIMULATING osteoclastic activity
calcitonin
decreases Ca+ levels in the blood by INHIBITING osteoclastic activity
simple fracture
no break in skin
open/compound fracture
breaks skin
colle fracture
break in distal radius beacuse of catching self from falling
greenstick fracture
bone breaks incompletely
stages of healing in bone fracture
hematoma formation, cartilage callus forms, spongy bone callus formation, remodeling: compact bone formation
hematoma formation
torn vessels hemorrhage, clotted blood forms at fracture site causing inflammation
cartilage callus
soft, osteoblasts and fibroblasts migrate to fracture, secretion of collagen fibers to connect broken bone ends, osteoblasts begin forming spongy bone
spongy bone callus
new bone trabeculae appear in soft callus, conversion to hard callus
remodeling
excess materials removed and compact bone is laid down to reconstruct shaft walls
osteopenia
bones become thinner and weaker with age
osteoporosis
severe bone loss
trabeculae
tissue elements that support or anchor a framework. provide Provide mechanical support, resist tension, and filter cells. help reduce weight and provide flexibility in spongy bone
