Bursting dynamics is a recurrent feature in natural phenomena, and a fundamental property ofphysiological systems across the human body. In the brain, the near synchronous firing of manyneurons gives rise to collective behaviors such as oscillations and neuronal avalanches, key featuresof the resting activity of cortical networks. In the first part of this talk, I will discuss recent workson avalanche dynamics in cortex slice cultures and in mammalian brains (humans and rats) acrossthe sleep-wake cycle, with a particular emphasis on the relationship between criticality and thetemporal organization of neuronal avalanches. I will then switch the focus from the isolated brain tothe integrated network of organs in the human body, where different complex physiological systemscontinuously interact to optimize and coordinate their function, and produce distinct physiologicstates. Organ-to-organ interactions occur at multiple levels and spatiotemporal scales and areessential for an optimal global behaviour of the network. Despite the importance of theseinteractions for maintaining health, little is known about their nature and dynamics. Here I willdemonstrate how physiologic network topology and systems connectivity can be associated toemerging behaviors representative of distinct states and functions. I will also show that universal,age-independent laws govern physiological networks at different levels of integration in the humanbody (brain-brain, brain-organ and organ-organ), and that transitions across physiological states areassociated with specific changes in the network organization. These investigations represent a firststep towards a holistic approach to human physiology that aims to associate distinct conditions tonetworks of interactions inferred from synchronous recordings of several organs across the humanbody, and predict their evolution in response to perturbations (e.g. organ failure, medicaltreatments).