👉 A fluid is a substance that takes the shape of its container but has no fixed volume, primarily composed of water or other liquids. The chief fluid in the human body is blood, a vital liquid that circulates through the circulatory system. Blood transports essential nutrients, oxygen, hormones, and waste products between cells and organs, playing a crucial role in maintaining homeostasis and supporting all bodily functions. It also acts as the body's defense mechanism, fighting off infections and injuries through white blood cells.
