How do unicellular organisms get the oxygen and nutritrients they need?

Which of the following blood vessels have valves?

Portal systems in humans start and end with which blood vessel?

What separates both sides of the heart?

Name the large artery that takes blood from the heart to around the body

Where does the pulmonary artery bring blood to?

Name the valves found in the arteries of the heart

Name the large chambers on the bottom of the heart

Name the blood vessels that brings oxygenated blood from the lungs to the left side of the heart

Name the blood vessels that brings blood back from the body to the right side of the heart.

What is the membrane that surrounds the heart?

Name the two chambers on the top of the heart

What supplies cardiac muscle with blood?

What prevents the backflow of blood from the right ventricle into the right atrium

What prevents the backflow of blood from the left ventricle into the left atrium?

What is another name for the pacemaker?

What does the pacemaker cause?

The AV node sends an impulse down what fibers?

The rhythmic expansion and contraction of the walls of the arteries as blood is forced through them is called the _____

What is hypertension?

What is the average resting heart-rate in adults in beats per minute?