Life's Blood.

This article, titled "Life's Blood," explores the history and understanding of blood circulation in the human body. It discusses how ancient doctors, including the Greek physician Galen, had limited knowledge about the circulatory system and believed in incorrect theories about the heart and blood. It wasn't until the 1600s that English doctor William Harvey discovered that the heart pumps blood throughout the body in a continuous circulation. The article also explains the functions of blood, including carrying oxygen, nutrients, and waste products, as well as the different types of blood cells. [Extracted from the article]