ALPHAMED PRESS IMAGE: BIOLOGICAL AGING OF TRACHEOBRONCHIAL TISSUE SPECIFIC STEM CELLS (TSC) AND THEIR TROPHIC UNIT, THE PSEUDOSTRATIFIED CONDUCTING AIRWAY EPITHELIUM. EACH INJURY ACTIVATES A SUBSET OF TSC WHICH PROLIFERATE AND UNDERGO TERMINAL DIFFERENTIATION. THUS, EACH INJURY CYCLE DEPLETES THE TSC POOL AND MANY INJURIES COMPROMISE EPITHELIAL REGENERATION. OVER TIME, BIOLOGICAL AGE EXCEEDS CHRONOLOGICAL AGE...
