During the systole phase of the cardiac cycle, the left ventricle contracts and blood is pumped into the aorta. which of these valves prevent a backflow of blood into the left atrium? a. aortic valve b. tricuspid valve c. mitral valve

true is the

huh

explanation:

these muscles maintain the blood pressure in the vessels. the smooth muscles are innervated by nerves of the autonomic nervous system. when the muscles contract, they cause vasoconstriction of the vessels and increase blood pressure. when the muscles relax, they enable vasodilation of the   blood vessels hence reduce blood pressure.