Which is correct about the contraction ssequence of the heart?
a. The contraction of all four chambers happens at the same time
b. The right atrium and ventricle contract at the same time, then the left atrium, then the left ventricle
c. Contraction occurs in a series, whereby the the right atrium, then right ventricle, then left atrium, then left ventricle are activated sequentially
d. The two atria contract at the same time, and as they are relaxing, the two ventricles contract together
e. The atria and the ventricles begin their contraction at the exact same time, but the atrial contraction only lasts half as long as the ventricular contraction
Answer: d. The two atria contract at the same time, and as they are relaxing, the two ventricles contract together
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Fill in the blank(s) with the appropriate word(s).
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Fill in the blank(s) with correct word
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