The second statement best explains the type of blood vessel and the function of these vessels' valves - <span>These are veins, which prevent the backflow of blood because the walls have little muscle to pump blood back to the heart.
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Veins are large blood vessels which carry blood back to the heart. <span>Veins have a system of valves to prevent back-flow.</span>
Answer:
it really depends on if you have recently had an injury to that hand or possibly over extended it doing an activity that you normally don't do. if there is no known injury you may want to have it checked out by your primary care doctor there's numerous different reasons that would cause the symptoms that you have listed and without more evaluation it would be hard to pinpoint the 3xact cause or how to repair or remedy this problem. more information would be highly appreciated and recommended.
Answer:static dynamic ballistic
Explanation:
Excitatory neurotransmitter? This question is too vague.
Answer:
increased risk of infertility in both males and females
