In the cardiac cycle,
a. the right atrium and the right ventricle contract simultaneously.
b. the two atria relax while the two ventricles contract.
c. the left atrium contracts before the right atrium.
d. all four chambers of the heart contract at the same time.
e. all four chambers of the heart are in systole at the same time.

Explain how the political influence of african americans leaders became weaker.

Which part of the neuron below is indicated by the arrow, and what is its function? hormones send chemical signals throughout the body to regulate other body processes. hormones are chemical signals that are sent throughout the body to regulate other body processes. hormones send electrical signals throughout the body to regulate other body processes. hormones are electrical signals that are sent throughout the body to regulate other body processes.

What molecule does hemoglobin decay into over time