1) These are responsible for the transportation of blood from the heart to all parts of the body. These vessels collect blood through capillaries and transport it towards the heart. These vessels connect arteries and veins.

2. All arteries carry oxygenated blood except pulmonary arteries which carry deoxygenated blood. All veins carry deoxygenated blood except pulmonary veins which carry oxygenated blood. These carry mixed oxygenated and deoxygenated blood.

3. Arteries have no valves in them except at the base of the pulmonary trunk and aorta. Valves are present in veins. These valves prevent the backflow of blood. There are no valves in them.

4. Arteries have high blood pressure. Veins have low blood pressure. There is falling pressure in them.

5. In arteries, waves of blood pressure or pulse due to heartbeat can be detected. There is no pulse. There is no pulse.

6. Blood flows rapidly between 400-500mm per second in the aorta and decreasing in arteries and arterioles. The rate of blood flow increases from smaller to larger veins. Blood flow is slowest which is less than 1mm per second.

7. Arteries have a smaller bore and thick walls. Veins have a larger bore and thin walls. Capillaries have a larger bore and the wall is of one cell in thickness.

8. There are thick muscle layers and elastic fibers present. The elasticity helps to change the pulsating flow of blood. There are thin muscle layer and less elastic fibers present in veins. So, they are less elastic. No muscles or elastic fibers are present.

9. There is no exchange of materials. There is no exchange of materials. These are responsible for the exchange of gases and nutrients.

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3 years ago