Thanks so much!
2007-11-15 07:16:27 · 8 answers · asked by Anonymous in Science & Mathematics ➔ Biology
because they are not needed? You only need values to control the direction of flow into and out of a pump like the heart.
2007-11-15 07:19:39 · answer #1 · answered by Brian K² 6 · 1⤊ 2⤋
Valves In Arteries
2016-12-29 09:03:40 · answer #2 · answered by lisk 3 · 0⤊ 0⤋
Ok. You might already know that veins have valves. Veins bring back blood to the heart at a very low pressure. These valves help to prevent a back flow of blood. Imagine if there was no valves in the veins, your blood would just remain ther your hands and feet and there won't be an even distribution of blood, especially to the brain. Arteries bring blood away from the heart under very high pressure, so these valves are not needed.
2007-11-15 07:28:42 · answer #3 · answered by Einstein 1 2 · 3⤊ 0⤋
Do Arteries Have Valves
2016-11-01 03:35:44 · answer #4 · answered by ? 4 · 0⤊ 0⤋
The aorta and the pulmonary artery both start at valves from the heart, but I don't know if you could say they "have" valves. A lot of arterial flow is regulated by smooth muscles which constrict to direct flow to other areas. These are a kind of valve too.
2016-03-16 05:37:17 · answer #5 · answered by Anonymous · 0⤊ 0⤋
Because in arteries, blood flow is pushed along by the blood pumped by the next beat of the heart. You do find valves in veins - the pressure is much, much lower, so especially in the legs, blood might flow backwards without them!
2007-11-15 07:30:30 · answer #6 · answered by kt 7 · 6⤊ 0⤋
Because they don't need them.. Veins have semilunar valves.
2007-11-15 08:02:33 · answer #7 · answered by Renaissance Man 5 · 1⤊ 0⤋
This Site Might Help You.
RE:
Why don't arteries have valves?
Thanks so much!
2015-08-18 10:07:25 · answer #8 · answered by Lavina 1 · 0⤊ 0⤋
Because of the high pressure of fast-flowing blood through them.
2014-10-09 04:16:44 · answer #9 · answered by Usama 3 · 0⤊ 0⤋