Cardiovascular system

What layer of the heart would be most immediately susceptible to infections caused by bacteria circulating in the blood?

endocardium

What vessels carry deoxygenated blood away from the heart?

pulmonary artery only

Which heart valves are NOT actively closed by the contraction of muscular structures?

semilunar valves

Which type of blood vessel has a 'pulse'?

the artery carry blood away from the heart, as a result the blood pulse through the arteries in response to the heart's beat.

From which chamber of the heart does blood leave to go to the lungs?

the right ventricle pumps the blood to the lungs where it becomes oxygenated

What physical feature of large systemic arteries (resistance vessels) makes them relatively more responsive to changes in intracellular calcium concentrations?

thick tunica media

How can the circulatory system promote heat retention/conservation, such as on a cold day?

vasoconstriction

Which type of blood vessel has valves inside?

veins contain valves that ensure blood flows in only on direction.

At the instant following the second heart sound, which heart valves are open?

all valves are closed

In terms of being open or closed, what is the state of the mitral and tricuspid valves (left and right atrioventricular valves, respectively) at the end of the first heart sound?

both are closed