2.65b Blood Vessels

1. The artery is carrying high blood pressure whereas the vein is carrying is carrying low blood pressure.
2. The capillary is the site for exchange.
3. The capillary walls are very thin, only one cell thick, easy for diffusion of gases.
4. The wall of the artery is thick and contains muscle. The lumein carries the blood is narrow. The muscle contracts, it maintains the blood pressure all the way to the organ.
5. Veins are collecting blood and returning them to the heart. The walls are thin compared to the artery. Large lumein which has low resistance, blood can flow through easily. They have valves to stop backflow.