Heart anatomy, circulation, and cardiovascular trivia.
Test your knowledge with these top questions!
When does most blood flow through the left coronary arteries?
The contracting left ventricle squeezes its small coronary vessels, so most left-side flow waits for diastole.
Which heart feature keeps chamber blood from supplying the whole heart muscle?
Oxygen diffuses only a short distance, so coronary vessels carry it deep into the thick myocardium.
Which valve opens from the left ventricle into the aorta?
The aortic valve closes after each beat to stop blood in the aorta from flowing back into the left ventricle.
What main job do the heart's two atria perform?
The right atrium receives blood from the body, while the left atrium receives blood from the lungs.
Which chamber forms the heart's pointed apex, normally directed down and left?
Doctors can often feel the apex beat between the fifth and sixth ribs on the left side.
Which chamber pair pumps blood to the lungs, then receives it back from the lungs?
The right ventricle starts pulmonary circulation; the left atrium ends it before blood enters the left ventricle.
Which autonomic branch uses the vagus nerve to slow the heart after exercise?
Parasympathetic signals release acetylcholine near the sinoatrial node, slowing the heart's natural pacemaker.
During which phase do all four heart valves stay closed while ventricular pressure rises?
Ventricular volume stays constant until rising pressure opens the aortic and pulmonary valves.
Which heart chamber first receives blood returning from the body?
The superior and inferior venae cavae empty oxygen-poor blood from the body into the right atrium.
The heart's septum helps preserve which key difference between its left and right sides?
By blocking mixing, the septum lets the left side send oxygen-rich blood to the body.