I would like to broaden the discussion here. I don't think it is true state, as Carl-Fredrik Bassøe suggests, that one can cleanly separate the different organ systems and there function. The human body is an integrated open system. One the one hand the function in one organ system part impacts on the function (and at times structure) of all other organ systems. Some of these are rather obvious, like cardiac failure resulting in confusional states due to cerebral hypoxia, others are much more subtle and have been elucidated on mainly in the psychoneuroimmunology literature. On the other, humans are part of wider open systems, as part of our family, or community, or country and so forth. We now understand how our environment impacts on our health - through constraining the possible biological responses provided by our genetic blueprint.
Our health systems clearly a complex adaptive systems, they organise themselves around the demands of disease management (rather than the health of our patients).
Complex adaptive systems thinking provides a framework to analyse the interconnected and interdependent structure and function of health and disease, and the way we structure healthcare within the structures of our society. Only if we understand these features across all scales can we make considered changes that have taken potential system wide consequences into account.
For more details see the following:
 Bennett JM, Reeves G, Billman G, Sturmberg JP. Inflammation, nature’s way to efficiently respond to all types of challenges: Implications for understanding and managing “the epidemic” of chronic diseases Frontiers in Medicine. 2018(5):316.
 Sturmberg JP, Picard M, Aron DC, Bennett JM, Bircher J, deHaven MJ, et al. Health and Disease—Emergent States Resulting From Adaptive Social and Biological Network Interactions. Frontiers in Medicine. 2019;6:59.
 Sturmberg JP. Health System Redesign. How to Make Health Care Person-Centered, Equitable, and Sustainable. Cham, Switzerland: Springer; 2018.