This book presents up to date major aspects of the chemoreceptor pathway from molecular and cellular signaling processes in the carotid body and other oxygen-sensing structures to central integration of chemosensory inputs and systemic implications. Because sustained changes in oxygen homeostasis are able to induce morphofunctional remodeling, which remains poorly understood but may provide further ways of research in physiology and pathophysiology, two sessions were devoted to the mechanisms involved in the processes of plasticity induced by long-term or intermittent hypoxia during the perinatal period or at adulthood.