Welcome to the course in non-alcoholic fatty liver disease. The essentials. I'm Nicolai Wewer Albrechtsen from University of Copenhagen. Together with my colleague, Professor Lise Lotte Gluud, from Hvidovre Hospital, we look forward to taking you on a guided tour through the human liver. The liver plays a vital role in the body homeostasis and the development of diseases. During this course, you will learn why the liver is a central organ in physiology and what happens in liver disease. We will focus on non-alcoholic fatty liver disease as it has a global impact now and in the coming years. Medical practitioners in the antiquity identified the liver as one of the three principal organs of the body, along with the heart and the brain. The Roman anatomist, Galen, suggested the liver as the core organ of the human body. Here we see how our ancestors thought of the liver as the central organ of the human body. We do agree with Galen. It was however, not until 1,400 years later that the anatomy of the human liver was really uncovered by Francis Glisson, who named the Glisson capture of the liver. Several scientists and clinicians have since that time contributed to our understanding of the human liver. Some you will hear from later on in this course. For several of our organs, the kidney, heart, and lungs, we have machines that enable continuation of life. But for our liver, there are simply too many functions for a machine to cover. Indeed, our liver is a complex and essential organ. During fetus development, the liver produces our blood cells and later in life, our liver helps us filter what we consume and what our environment exposes us to. Research from the last decades have shown that the liver possesses multiple roles in maintaining body homeostasis, coagulation, digestion, glucose homeostasis, and so on. Emerging science now puts the liver as a forefront organ in the control of appetite and metabolism by interacting with other organs via chemical molecules such as proteins, peptides, and metabolites, which may also reflect the health of the liver as discussed in the module on diagnostic. Early and accurate diagnostic of non-alcoholic fatty liver disease and other liver diseases are therefore of immense importance. Likewise, treatment of non-alcoholic fatty liver disease is important and will be showcased from pharmacological and non-pharmacological perspective in some of the later modules. In the final part of this course, we will discuss complications to cirrhosis and what to do when the liver fails. We will also cover the relevance of NAFLD to other diseases such as type two diabetes. We hope you will enjoy a dedicated course on non-alcoholic fatty liver disease. To kick off, Professor Jens Juul Holst, a leading physiologist, will teach us about the metabolic function of the human liver.