A computer-generated image of red blood cells. Nitric oxide—known by the formula NO—is so vital for humans’ internal physiological processes that it was crowned Molecule of the Year in 1992. It plays ...

While the human body doesn’t replace itself every seven years in a uniform way, it does engage in constant renewal.

Renin-angiotensin system, or RAS, is a physiological mechanism essential to human body function. The SARS-CoV-2 virus causes overactivation and malfunction of this system. The RAS regulates innate ...

An organ is a group of tissues that work together to perform a specific task in the body, such as digesting nutrients or producing chemical messengers that enable brain cells to communicate. Although ...