From understanding the effect of aneurysms and what causes strokes to simulating and constructing artificial organs, maths has a huge role to play in developing new medical treatments. But one key part of the human physiology is the study of blood. It’s fairly obvious that blood is key to life – if you bleed too much you die. It has been studied by many eminent figures, from Aristotle who believed blood was required to transport heat around the body to Poiseuille who derived derived a simplified model of mathematical flow in a pipe to describe flow through arteries. We now understand that blood carries oxygen and essential nutrients to our cells, and carries waste products such as urea away to be processed.