blood flow to heart diagram

August 03, 2026

General

Blood | Definition, Composition, Functions, & Facts | Britannica — Blood | Definition, Composition, Functions, & Facts | Britannica

Blood is a liquid connective tissue made up of blood cells and plasma that circulate inside the blood vessels under the pumping action of the heart. Blood is a specialized fluid that constantly flows throughout your body. It’s made of plasma, red blood cells, white blood cells and platelets. 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 of the body, and transports metabolic waste products away from those same cells. [1] Blood is composed of blood cells suspended in plasma. In this week's episode, Blood editor Dr. James Griffin interviews Drs. Hanny Al-Samkari and Xin Zhou on their latest articles published in Blood. 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 cells are suspended in a liquid matrix known as plasma. For related background details, please refer to our report on 2017 ford focus fuse box diagram. 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% plasma and 45% blood cells. About 7% to 8% of your total body weight is blood. The solid part of your blood contains red blood cells, white blood cells, and platelets. Red blood cells (RBC) deliver oxygen from your lungs to your tissues and organs. A blood type (also known as a blood group) is a classification of blood based on the presence and absence of antibodies and inherited antigenic substances on the surface of red blood cells (RBCs).