Using beautiful 3D visualisation to take a look inside the human body, this App explores the difficulties in defining a disease. Can disease exist without illness? Does disease precede symptoms? ...And what is health? Is health merely the absence of disease? We explore the concept of homeostasis, or equilibrium in the body, and the fact that disease can be physiological or psychological. Using lobar pneumonia as an example, we present the acute inflammatory response stimulated by the bacterium 'streptococcus pneumoniae' to demonstrate the interconnectedness of biological processes within cells, tissues and organs. That is, a change in one will effect a change in another.

After viewing the video, to assist your understanding of this topic, you can complete a Quiz consisting of 20 multiple choice questions. The Quiz includes an optional "Hint" button which enables you to review the portion of the video related to the question. However if a "Hint" is used to answer the question, the maximum score out of 1 for a correct answer will be 0.5. The Quiz also includes a Check button so you can check immediately whether or not you answered the question correctly, however if you use the Check button you cannot change your answer. You also have the option to Tweet your results to others.