2007-02-14 14:07:18 · 8 answers · asked by Jessica N 2 in Science & Mathematics ➔ Biology
The walls of an artery are muscular because they have to maintain some pressure to keep the blood flowing at a steady rate. The artery is delivering oxygen to the cells, and this needs to be precisely regulated.
The vein is mainly returning blood to the heart. It may be carrying food to the cells and waste to the kidneys and lungs; but this doesn't require as much precision in terms of speed. Not needing the muscles, the walls are thinner.
2007-02-14 15:22:24 · answer #1 · answered by The First Dragon 7 · 1⤊ 0⤋
Because the blood is under a higher pressure as it goes out through the arteries than it is as it returns to the heart in the veins.
2007-02-14 14:17:30 · answer #2 · answered by Anonymous · 0⤊ 0⤋
The arteries are thicker so they can stand up to the huge preassure of blood from the hear, but by the time the blood gets to the veins its a lot slower and have very little preassure. I think the thinness also lessens resistance to the weak blood flow. The veins have valves to stop the blood flowing backwards.
2016-05-24 00:33:30 · answer #3 · answered by Anonymous · 0⤊ 0⤋
Because they are more muscular than their corresponding veins, a function that is used by the body to regulate blood flow and temperature maintaining homeostasis.
If you look at
http://www.rit.edu/~japfaa/blood_vessels.jpg
you'll see that the muscular layer of the artery is significantly thicker than the vein.
2007-02-14 14:36:54 · answer #4 · answered by Jenny M 2 · 0⤊ 0⤋
Arteries are under more pressure than that of the corresponding veins.
2007-02-14 14:45:52 · answer #5 · answered by Anonymous · 0⤊ 0⤋
it is because the blood flowing thru the arteries is under a lot more pressure thanthe blood flowing thru the veins. the blood in arteries is pushed by the heart, the veins are working against gravity and actually contain "one-way" valves so that the blood can't go backwards.
2007-02-14 14:15:23 · answer #6 · answered by Bio-student Again(aka nursegirl) 4 · 1⤊ 0⤋
Because through the ages, since the beginning of life, numerous random mutations has made it like that.
Or you can just say that they have higher blood pressure.
2007-02-14 14:15:58 · answer #7 · answered by Anonymous · 1⤊ 1⤋
because it is used to pump blood while the returning blood does not need to be forced
2007-02-14 14:14:53 · answer #8 · answered by Dataguard 2 · 1⤊ 1⤋