Human Ecology in Space Flight, Band 2

activity adaptation amount apatite astronauts BASSETT bedrest biological blood body bone mass bone resorption BROWN calcis calcium intake CALLOWAY cardiovascular cent changes collagen cortex cortical cortical bone crystal demonstrated diuresis Doctor Mack effects electrical electrodes endocrine energy engineering environment excretion experiments extracellular factors fatty acids FENN FIGURE fluid fluoride formation FREMONT-SMITH GERATHEWOHL going hormone hypercalcemia immobilization inactivity increase individual INGELFINGER LAMBERTSEN LIVINGSTON loss MARGEN matrix MCCALLY measurements mechanical metabolic mineral muscle NASA nervous system neuropil nitrogen normal organism osteoclasts osteocyte osteoporosis osteoprogenitor cell oxygen parathyroid parathyroid hormone patients period phosphorus physical physiological potential probably problem prolonged protein question RAHN receptor response reticular ROGERS sciences sensory serum signal simulated skeleton space flight stimulus stress studies subjects temperature tension thing tion tissue urinary calcium urine URIST vertebrates VINOGRAD vitamin vitamin D weightlessness WHEDON