danielabardot
contestada

Why do veins also have valves?

to keep the blood from circulating too fast
to regulate contractions of the heart
to keep the veins from losing blood
to prevent gravity from pulling the blood towards the feet

Respuesta :

judygachanja

Answer:

the last choice.

Explanation:

veins have valves because venous pressure is often not great enough( as the blood must overcome gravity and other forces) to return the blood to the heart.

valves mainly prevent the back flow of blood.

kiillua

Answer:

The answer is to prevent gravity from pulling the blood towards the feet.

Explanation:

Since the gravity is "pulling" the blood away from the heart, these vales function to keep the blood from flowing backward.

If the answer is wrong or ,you dont understand welp-

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