Blood don't flow inside the healthy vessels because due to anticlotting factor and also due to vessels the vessels are so much strong and can broken only by any serious accidentIf blood get start to flow outside the vessels then the situation is called internal bleeding...
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Because of naturally occurring anticlotting agent heparin..
It allow blood to keep flowing & not clotting.
If blood clot inside it lead to heart attack or even vein or artery burst.
1.the rate of breathing increases during vigrous excersice beacause we do a lotof work in a less period of time.
7) the rate of breathing during vigorous exercise increases by about 20 to 25 times per minute it is because during vigorous exercise the demand for oxygen increases breathing occurs involuntarily but its rate is controlled by the respiratory centre of the brain
For blood to clot your body needs blood proteins called clotting factors and blood cells called platelets .normally platelets clump together to form a plug at the sits of a damaged or injured blood vessels when the blood doesn't clot excessive or prolonged bleeding can occur.
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because vessels are very thin so if blood will clot there it will creat a problem in transportation of blood.
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