This heart quiz has 60 free questions with answers and covers the organ from every angle: how it is built (chambers, valves, the septum, the arteries that feed it), how it works (the natural pacemaker, systole and diastole, the lub-dub of the valves, how much blood it moves in a day), and how it goes wrong and gets fixed (blood pressure numbers, cholesterol, heart attacks versus cardiac arrest, stroke, CPR and defibrillators, bypasses, pacemakers and the first transplant). There is a stretch of medical history too, from William Harvey and the first stethoscope to the doctor who threaded a catheter into his own heart, and a few detours into animal hearts: the whale with the biggest, the octopus with three, the hummingbird with the fastest. Around a third of the questions suit a school health class or a family table; the rest climb to the level of a nursing student or a keen pub-quiz team. Every answer has been checked against Wikipedia and medical reference pages, and each question shows its source once you have answered, so it is safe to use for a heart-month event, a classroom or a quiz night.
30 of 60 questions with answers and explanations. Play the quiz
Q 01How many chambers does the human heart have?
Four
The upper two are the atria and the lower two the ventricles; fish get by with two and most reptiles with three.
Q 02What are the two upper chambers of the heart called?
Atria
The word is Latin for an entrance hall, which is roughly what they are: blood arrives there before being passed down to the pumping chambers below.
Q 03Roughly how much does an adult human heart weigh?
250-350 grams
That is about the weight of a large orange, and it is famously about the size of the owner's clenched fist.
Q 04What is the normal range for an adult's resting heart rate?
60 to 100 bpm
Fitness pushes the number down: an ultra-trained endurance athlete can tick over at 37 or 38 beats a minute.
Q 05Which structure acts as the heart's own natural pacemaker, setting the normal sinus rhythm?
The sinoatrial node
It sits in the wall of the right atrium and would fire about 100 times a minute if the nervous system did not rein it in to a resting 70 or so.
Q 06Which chamber of the heart has by far the thickest muscular wall?
Left ventricle
The right side only has to push blood next door to the lungs; the left has to drive it out to the toes and back.
Q 07What is the name of the sac that surrounds the heart?
Pericardium
Inflammation of it is pericarditis, which classically produces chest pain that eases when the patient sits up and leans forward.
Q 08The wall of muscle that separates the heart's two lower pumping chambers from each other is called what?
The interventricular septum
A hole in it at birth is a ventricular septal defect, the most common congenital heart defect and one that often closes on its own.
Q 09The myocardium, the middle layer of the heart wall, is made of which type of tissue?
Involuntary striated muscle
It is striped like the muscle in your arm but works without conscious control like the muscle in your gut, a combination found nowhere else in the body.
Q 10Which of these sits between the right atrium and the right ventricle?
Tricuspid
As the name says it has three flaps; its partner on the left side has only two, which is why that one is also called the bicuspid valve.
Q 11Because it has two cusps, the mitral valve is also known by what name?
Bicuspid
The name mitral comes from its resemblance to a bishop's mitre.
Q 12Roughly how long after conception does the embryonic human heart begin to beat?
About 3 weeks
That is around five weeks after the last menstrual period, often before the pregnancy has been confirmed.
Q 13Which parasympathetic nerve, named from the Latin for wandering, acts to slow the heart rate?
The vagus nerve
Its name means wandering, and stimulating it hard enough (a sudden fright, straining, or bearing down) can drop the heart rate enough to make someone faint.
Q 21On an ECG trace, the QRS complex represents the electrical depolarization of which part of the heart?
The ventricles
The smaller P wave before it is the atria firing, and the T wave after it is the ventricles resetting for the next beat.
Q 22In 1929 Werner Forssmann performed the first human cardiac catheterization. On whom?
Himself
He threaded a tube up a vein in his own forearm into his heart, walked to the X-ray room to prove it, was sacked for it, and shared a Nobel Prize for it in 1956.
Q 23In which city did Christiaan Barnard perform the first human heart transplant in 1967?
Cape Town
Q 14What is a resting adult heart's average cardiac output, i.e. blood pumped per minute?
About 5 litres
That works out at roughly 7,000 litres a day, enough to fill a small road tanker, from an organ the size of a fist.
Q 15What is the largest artery in the human body, carrying blood out of the heart's main pumping chamber?
The aorta
In an adult it is roughly the diameter of a garden hose where it leaves the heart.
Q 16The 'lub' of the heart's 'lub-dub' sound is caused by the closing of which pair?
The mitral and tricuspid valves
The 'dub' that follows is the aortic and pulmonary valves snapping shut as the ventricles finish contracting.
Q 17A heart murmur is a sound produced by what?
Turbulent blood flow
Many murmurs are harmless, especially in children, but some point to a leaking or narrowed valve.
Q 18The stethoscope was invented in 1816 by René Laennec in which country?
France
The first one was a simple wooden tube; Laennec came up with it because he was uncomfortable pressing his ear directly to a female patient's chest.
Q 19Which English physician first fully described blood circulation in his 1628 book De Motu Cordis?
William Harvey
The book ran to just 72 pages and was dedicated to King Charles I, whose personal physician he was.
Q 20Which Dutch physiologist's 1903 string galvanometer made precise ECGs possible, winning a 1924 Nobel?
Willem Einthoven
The letters P, Q, R, S and T that label the waves on every ECG trace today come from his notation.
The patient, grocer Louis Washkansky, lived 18 days and died of pneumonia; Barnard's second patient survived more than 18 months.
Q 24At which university's hospital did Norman Shumway perform the first US adult heart transplant in 1968?
Stanford
Shumway had spent a decade developing the technique in dogs; Barnard, who had studied his methods, beat him to a human patient by a month.
Q 25Roughly how many heart transplants are performed worldwide each year?
About 5,000
The number is limited by donors, not demand; the 1983 arrival of the anti-rejection drug cyclosporine is what turned the operation from an experiment into routine care.
Q 26The first fully implantable pacemaker was fitted in October 1958 in which country?
Sweden
The patient, Arne Larsson, went through 26 pacemakers and died in 2001 aged 86, outliving both the surgeon and the inventor.
Q 27What was the permanent artificial heart Barney Clark received in December 1982 called?
Jarvik-7
Clark lived 112 days tethered to a 400-pound pneumatic drive console.
Q 28In a coronary bypass operation, which vessel from the leg is most commonly harvested to use as the graft?
The great saphenous vein
Arteries such as the internal mammary stay open longer, but the leg vein is long, easy to reach and the leg manages without it.
Q 29Cardiovascular disease is the top killer worldwide. Roughly how many deaths did it cause in 2015?
About 18 million
That was just under a third of all deaths on Earth that year, and it is estimated that up to 90 percent of cardiovascular disease is preventable.
Q 30Which is the only continent where cardiovascular disease is NOT the leading cause of death?
Africa
Infectious diseases still claim more lives there, though heart disease is climbing fast as diets and cities change.