A quintessential textbook which connects the different functions, systems and interactions of the human body as whole and emphasises the importance reconnecting human health with nature Human structure, function and dysfunction is commonly taught under the headings of anatomy, physiology (including biochemistry and pharmacology), and pathology. Whilst these divisions seem logical, the drawback is that they encourage us to consider parts of the body in isolation. Organs and tissues are divided into “systems” for ease of description, but relatively little time is spent learning how body systems relate to one another and to the wider world. The result is a sense of disconnection between the body and the environment as a whole, and this in turn makes it for us hard to assimilate the impact of more recent knowledge - such as that we have several functioning “brains” capable of remembering things and taking decisions in different parts of the body in addition to our “normal” brain; or that our microbiomes - made up of cells that are not genetically part of us - can have a massive impact on health, and on the way we function. An ecosystem consists of all the living components of a system and the physical environments with which they interact. Its components are linked together through nutrient cycles and energy flows. Things are not separated into discrete systems - everything is a symphony of interaction, feedback and adjustment. The Human Ecosystem explores the fundamental processes and interactions that maintain health and enable us to recover from illness. It considers human structure and function based on an understanding that human beings are complex, intelligent, adaptive, self-healing, networked ecosystems in which information is transferred and acted upon at incredible speed. Above all, it presents us as part of the wider ecosystem, interdependent with Nature and all living things for our health and survival.