Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away …

Dec 15, 2025 · Blood is a fluid that transports oxygen and nutrients to cells and carries away carbon dioxide and other waste products. It contains specialized cells that serve particular functions. These …

Blood is a specialized fluid that constantly flows throughout your body. It’s made of plasma, red blood cells, white blood cells and platelets.

Detailed information on blood, including components of blood, functions of blood cells and common blood tests.

The main job of red blood cells, or erythrocytes, is to carry oxygen from the lungs to the body tissues and carbon dioxide as a waste product, away from the tissues and back to the lungs.

It has four main components: plasma, red blood cells, white blood cells, and platelets. The blood that runs through the veins, arteries, and capillaries is known as whole blood—a mixture of about 55% …

The body contains about 5 to 6 quarts (about 5 liters) of blood. Blood performs various essential functions as it circulates through the body: Once blood is pumped out of the heart, it takes 20 to 30 …