The heart: chambers, valves and vessels

Every question, with the answer explained

The full set, for revision or for reading straight through. The correct answer is marked, and the explanation says why.

1. 1. How many chambers does the human heart have?

   • Two
   • Three
   • Four
   • Six

   Four. Two atria on top receiving blood, two ventricles below pumping it out. The right side serves the lungs, the left side the body.

2. 2. Which chamber pumps blood into the aorta?

   • Right atrium
   • Right ventricle
   • Left atrium
   • Left ventricle

   Left ventricle. The left ventricle drives blood into the aorta and around the whole body. It is the thickest-walled chamber for that reason.

3. 3. Which valve sits between the left atrium and left ventricle?

   • Tricuspid valve
   • Mitral (bicuspid) valve
   • Pulmonary valve
   • Aortic valve

   Mitral (bicuspid) valve. The mitral valve, with two cusps. The tricuspid, with three, sits in the equivalent position on the right side.

4. 4. Deoxygenated blood returns from the body to the heart through:

   • The pulmonary veins
   • The superior and inferior vena cava
   • The aorta
   • The pulmonary artery

   The superior and inferior vena cava. The venae cavae empty into the right atrium. The pulmonary veins are the exception that surprises people — they carry oxygenated blood, from the lungs to the left atrium.

5. 5. Which artery supplies the heart muscle itself?

   • The coronary arteries
   • The carotid arteries
   • The pulmonary artery
   • The renal arteries

   The coronary arteries. The coronary arteries arise from the aorta just above the aortic valve. Narrowing of these is what causes angina and heart attacks.

   What does “atherosclerosis” mean?

6. 6. Where does the heart's normal electrical impulse begin?

   • The atrioventricular node
   • The sinoatrial node in the right atrium
   • The bundle of His
   • The left ventricle

   The sinoatrial node in the right atrium. The sinoatrial node is the natural pacemaker. Its rate sets the heart rate, and disease of it or of the conducting pathway below produces many arrhythmias.

   What does “arrhythmia” mean?

7. 7. What is the pericardium?

   • The heart's inner lining
   • The double-layered sac surrounding the heart
   • The muscular wall
   • A heart valve

   The double-layered sac surrounding the heart. The pericardium is the fibrous sac around the heart. Inflammation of it — pericarditis — causes sharp chest pain that typically eases on leaning forward.

8. 8. Blood leaving the right ventricle goes to:

   • The body
   • The lungs, via the pulmonary artery
   • The liver
   • The brain

   The lungs, via the pulmonary artery. The right ventricle sends blood to the lungs to be oxygenated. The pulmonary artery is the other exception — an artery carrying deoxygenated blood.