Arteries, Capillaries and Veins
- Carry blood from the heart to the body.
- Thick and muscular walls with elastic tissue to cope with high pressure produced by heartbeat.
- The inner lining (endothelium) is folded, allowing the artery to expand - also helps cope with pressure.
- All arteries carry oxygenated blood except for the PULMONARY - deoxygenated to the lungs.
- Substances like glucose and oxygen are exchanged between cells and capillariesvso they are adped for efficient diffusion (one cell thick)
- Capillaries branch off of arteries and connect to veins.
- Veins take blood back to the heart under low pressure.
- They are wider than arteries with very little elastic or muscle tissue.
- Veins contain valves to stop the blood flowing backwards.
- Blood flow through the veins is helped by contraction of the body muscles surrounding them.
- All veins carry deoxygenated blood except for the PULMONARY - oxygenated blood to the heart from the lungs.