fractures that occur in bones that are already weakened
fractures that occur in the young at the epiphyseal plate because the plate is weaker than the ligaments holding it together
3 stages of fracture healing?
functions of synovial fluid?
supply oxygen and nurtients, removes wastes, clean up damaged parts, decrease friction in join movement
fluid filled sac that acts as a ball bearing found between bone muscle, bone-tendon, bone-ligament
how is the joint capsule contructed?
an outer layer of fibrous connective tissue, an inner layer of synovial membrane
what type of joint has the greatest range motion? least range?
ball socket- greatest range
hinge- least range
example of the 6 types of movable joints?
balls and socket- hip
saddle- base of thumb
gliding- wrist bones
pivot- C1 and C2
most important stabilizer of the glenohumeral joint?
what is the nurse-maid's elbow?
radial head dislocation
anatomy of the hip joint?
head of femur sits deep in acetabulum, held in place by ilio-, ischio-, and pubo- fermoral ligaments
why is hip disolcation an orthopehdic emergency?
compromise of blood supply to head of femur because of injury to ligamentum teres
describe meidal and lateral menisci.
hyaline catilage cushions between the articular surfaces of the femur and tibia
pads act as shock absorbers
function of the anterior and posterior cruciate ligaments?
to prevent excessive forward or backwardmovement of the femur on the tibia
what protects the front of the knee?
quadriceps, tendon, and patella
anatomy of a muscle cell?
elongate, multiple nuclei, terminal cisternae wrapped around filament bundles, cell membrane extensions called T tubules running through the cell against the terminal cisternae
anatomy of a sarcomere?
Z discs of titin, attached to actin filaments that run toward the center of the sarcomere but do not reach it; mysoin filaments in the middle, covering the area that actins leave open, titin strands attaching mysoin ends to the Z disc
What connects the sacromere to the outer covering of the muscle cell?