BIO 210 : Chapter 7 Skeletal System

remodeling units

adjacent osteoblasts and osteoclasts

Alkaline phosphatase

enzyme for mineralization in bone deposit

Testosterone & Estrogen

2 hormones that promote adolescent growth spurts, end growth by inducing epiphyseal plate closure

osteoporosis

A condition in which the body's bones become weak and break easily.

parathyroid hormone

A hormone of the parathyroid gland that removes calcium from bone regardless of bone integrity

epiphyseal plate closure

Bone lengthening ceases; Requires presence of cartilage

nondisplaced

Fracture: ends retain normal position

leptin

Hormone released by adipose tissue; May play role in bone density regulation by inhibiting osteoblasts

calcium homeostasis

Maintenance of a stable level of calcium in the blood

denosumab

Monoclonal antibody shown to reduce fractures in men with prostate cancer and improves bone density in elderly

transcytosis

allow release into interstitial fluid and then into blood

intramembranous ossification

bone develops from fibrous membrane; bones called membrane bones; flat bones

endochondral ossification

bone forms by replacing hyaline cartilage; bones called cartilage bones; forms most skeleton

bone deposit

bone remodeling where new bone matrix is deposited by osteoblasts

bone resorption

bone remodeling where the removal of minerals and collagen fibers from bone by osteoclasts

nonresponsiveness

calcium levels too high

hyperexcitability

calcium levels too low

calcium

chemical that functions in nerve impulse, blood clotting, muscle contraction, secretion by glands and nerve cells and cell division

bisphosphonates

decrease osteoclast activity and number; Partially reverse osteoporosis in spine

hypercalcemia

deposits of calcium salts in blood vessels that result in an abnormally high level of calcium in the blood

lysosomal enzymes

digest matrix and protons in bone resorption

statins

for lowering cholesterol also increase bone mineral density.

complete

fracture broken all the way through

open

fracture where skin in penetrated

closed(simple)

fracture where skin is not penetrated

incomplete

fracture. not broken all the way through

growth hormone

hormone most important hormone in stimulating epiphyseal plate activity in infancy and childhood

thyroid hormone

hormone that modulates activity of growth hormone, ensuring proper proportions

appositional growth

increase in bone thickness

interstitial growth

increase in length of long bones

serotonin

neurotransmitter regulating mood and sleep; secreted into blood after eating

bone homeostasis

older bones become more brittle; Consists of bone remodeling and bone repair

apoptosis

once resorption is complete osteoclasts undergo ___________.

closed reduction

physical manipulates to correct position

ossification

process of bone tissue formation

calcitonin

produced by parafollicular cells of the thyroid gland; lowers blood calcium levels

mesenchymal cells

stem cells that respond to injury or infection that forms fibrous. connective tissue

open reduction

surgical pins or wires secure ends

displaced

the fractured bone parts are out of normal alignment

immobilization

treatment of fracture by cast or traction for healing

reduction

treatment of fracture where realignment of broken bone ends

calcification front

type of bone deposit; abrupt transition zone between osteoid seam and older mineralized bone

osteoid seam

type of bone deposit; unmineralized band of bone matrix

osteomalacia

when bones are poorly. mineralized, not enough calcium, become soft and week causing pain when bearing weight

rickets

when having bowed legs and other bone deformities, bone ends. enlarged. and abnormally long, and is caused by vitamin D deficiency.

primary ossification center

where blood vessel infiltration of perichondrium converts it to periosteum >>> underlying. cells change to osteoblasts

resting zone

zone of cartilage that has cartilage on epiphyseal side of. epiphyseal plate

calcification zone

zone of cartilage that has surrounding cartilage matrix calcifies, chondrocytes die and deteriorate

ossification zone

zone of cartilage where chondrocyte deterioration leaves lone spicules of calcified cartilage at epiphysis-diaphysis junction

hypertrophic zone

zone of cartilage where older chondrocytes closer to diaphysis and their lacunae enlarge and. ended >> interconnecting spaces

proliferation zone

zone. of. cartilage that rapidly divides pushing epiphysis away from diaphysis. >> lengthening