1 adj Social means relating to society or to the way society is organized. ADJ n. ...the worst effects of unemployment, low pay and other social problems., ...long-term social change., ...changing social attitudes., ...the tightly woven social fabric of small towns., ...research into housing and social policy.
The human circulatory system (simplified). Red indicates oxygenated blood carried in arteries, blue indicates deoxygenated blood carried in veins. Capillaries, which join the arteries and veins, and the lymphatic vessels are not shown.
Pulmonary circulation circuit showing oxygen and carbon dioxide exchange to and from the lungs. The blood vessel network of the body is composed of arteries, arterioles (small arteries), veins, venules (small veins), and capillaries. Arteries carry blood from the heart; veins carry blood to the heart; capillaries link the arteries and the veins.