30.4 Blood Vessels and Transport Arteries, veins, and capillaries transport blood to all parts of the body.

30.4 Blood Vessels and Transport Arteries carry blood away from the heart. –blood under great pressure –thicker, more muscular walls ARTERY VEIN CAPILLARIES arteriole venule endothelium connective tissue smooth muscle valve

30.4 Blood Vessels and Transport Veins carry blood back to the heart. –blood under less pressure –thinner walls, larger diameter –valves prevent backflow ARTERY VEIN CAPILLARIES arteriole venule endothelium connective tissue smooth muscle valve

30.4 Blood Vessels and Transport Capillaries move blood between veins, arteries, and cells. ARTERY VEIN CAPILLARIES arteriole endothelium connective tissue smooth muscle venule valve

30.4 Blood Vessels and Transport Blood Components –plasma –red blood cells –white blood cells –platelets red blood cells, white blood cells, and platelets plasma * Blood transports materials

30.4 Blood Vessels and Transport Plasma –55% of Blood –molecules diffuse into and out of it –contains proteins and clotting factors –~90 % water

30.4 Blood Vessels and Transport Red blood cells –transport oxygen to cells and carry away carbon dioxide –have no nuclei and contain hemoglobin

30.4 Blood Vessels and Transport White Blood Cells fight pathogens and destroy foreign matter. red blood cell platelet white blood cell

30.4 Blood Vessels and Transport Platelets help form clots that control bleeding. platelets fibrin red blood cell white blood cell