The human body is made up of 37 trillion cells or so, in four main types of tissue. They're found in 78 organs, including the vital heart, brain, kidneys, liver, and lungs, and nearly a dozen systems – from the circulatory to the digestive, immune, muscular and skeletal. Learn how the body’s parts work, what could go wrong, and how best to keep them healthy for a lifetime.
What You Need To Know
Central nervous system
A fifth taste, umami, was identified in
by Japanese scientist Kikunae Ikeda, a Tokyo Imperial University professorread more >