Why is the structure of arteries different from that of capillaries?

Answer 1

The structure of arteries and capillaries are different because their functions are different. Arteries carry blood from the heart, so their walls have to withstand high blood pressure. They also have to maintain blood pressure to ensure a continuous blood flow. Therefore, their three-layered walls are strong, elastic, have smooth muscle cells and collagen fibres. Capillaries exchange material (oxygen, carbon dioxide, nutrients etc.) between the blood and interstitial fluid. To be able to carry out this function, they have to have very thin, permeable walls.

Answer 2

Capillaries are single layer of endothelial cells and their diameter is upto 1 mm whereas arteries are composed of thick layered wall consisting of three layers. The outermost layer consists of connective tissue , the middle layer consists of elastic and smooth muscle tissue whereas the innermost layer consists of a single layered smooth endothelial tissue.

Answer 3

Veins, arteries, and capillaries are all blood vessels. The main difference between veins and arteries is that in veins blood flows toward the heart, while in arteries blood is flowing away from the heart. Arteries therefore contain oxygenated blood, while veins are bringing blood back to the heart to get more oxygen after the cells deliver the oxygen to cells all over your body. They are also structured differently. Arteries are structured to actually pump blood to help with blood flow through the body. This is why you can feel your "pulse" in your wrist. Veins do not pump blood; blood is simply forced through by the strength of the heart and arteries pumping the blood behind it. In order to prevent backflow (or blood flowing away from the heart within the vein), veins contain valves which only open in one direction, therefore only allowing blood to flow in one direction. You can think of them as a V-shaped stopper, where the point of the V opens to allow blood to flow downward, but not upward.

Capillaries are very, very tiny blood vessels, so small that only a single blood cell can pass through at a time. They help blood deliver the oxygen they carry directly to a single cell because they are so small.

Answer 4

The importance of capillaries lies in their very thin walls. Unlike arteries and veins, capillary walls are thin enough that oxygen and nutrients in your blood can pass through the walls to the parts of your body that need them to work normally.

Capillaries' thin walls also allow waste products like carbon dioxide to pass from your body's organs and tissues into the blood, where it's taken away to your lungs.