Click image to open full size
Anatomy of the Heart (Deep) Cheat Sheet
A printable reference covering heart chambers, valves, blood flow, coronary circulation, cardiac conduction, and major vessels for grades 10-12.
Related Labs
This cheat sheet covers the deep anatomy of the human heart, including chambers, valves, vessels, circulation pathways, and the electrical conduction system. Students need these structures to understand how the heart pumps blood, separates oxygen-rich and oxygen-poor blood, and supports the whole body. It is especially useful for connecting anatomy names to functional pathways in medical science, biology, anatomy, and physiology courses. The most important concept is that blood follows a one-way route through the right heart, lungs, left heart, and body. Valves prevent backflow, while the myocardium provides the force for contraction. The coronary arteries supply oxygen to the heart muscle itself, and the conduction system coordinates each heartbeat through a timed electrical sequence.
Key Facts
- Blood flow pathway: body to superior and inferior vena cava to right atrium to tricuspid valve to right ventricle to pulmonary valve to pulmonary arteries to lungs.
- Oxygenated blood flow pathway: lungs to pulmonary veins to left atrium to mitral valve to left ventricle to aortic valve to aorta to body.
- The right side of the heart pumps deoxygenated blood to the lungs, while the left side pumps oxygenated blood to the systemic circulation.
- The atrioventricular valves are the tricuspid valve on the right and the mitral valve on the left, and they prevent backflow into the atria.
- The semilunar valves are the pulmonary valve and aortic valve, and they prevent backflow from the arteries into the ventricles.
- The left ventricle has the thickest myocardium because it must generate the highest pressure to pump blood through the entire body.
- Cardiac conduction pathway: SA node to AV node to bundle of His to right and left bundle branches to Purkinje fibers.
- Coronary circulation supplies the myocardium with oxygen and nutrients, mainly through the right coronary artery and left coronary artery branches.
Vocabulary
- Myocardium
- The thick muscular layer of the heart wall that contracts to pump blood.
- Septum
- The internal wall that separates the right and left sides of the heart.
- Atrioventricular valve
- A valve located between an atrium and a ventricle that prevents blood from flowing backward into the atrium.
- Semilunar valve
- A valve at the exit of a ventricle that prevents blood from flowing backward from an artery into the heart.
- Coronary artery
- A blood vessel that delivers oxygen-rich blood to the heart muscle.
- SA node
- The sinoatrial node is the heart's natural pacemaker that starts each electrical impulse for a heartbeat.
Common Mistakes to Avoid
- Confusing arteries with oxygenated blood is wrong because arteries are defined by carrying blood away from the heart, not by oxygen level. The pulmonary arteries carry deoxygenated blood to the lungs.
- Reversing the right and left sides of the heart is wrong because anatomical left and right refer to the patient's body, not the viewer's perspective on a diagram.
- Placing the mitral valve on the right side is wrong because the mitral valve is between the left atrium and left ventricle. The tricuspid valve is on the right side.
- Saying the heart gets oxygen directly from blood inside its chambers is wrong because the myocardium is supplied mainly by the coronary arteries on the heart surface.
- Skipping the AV node in the conduction pathway is wrong because the AV node delays the signal so the atria can finish contracting before the ventricles contract.
Practice Questions
- 1 Trace the path of one red blood cell starting in the superior vena cava and ending in the aorta, naming each chamber and valve it passes through.
- 2 A patient has a blocked left anterior descending artery. Which tissue is directly at risk, and why is coronary blood flow necessary?
- 3 If the left ventricular pressure is 120 mmHg during systole and the aortic pressure is 80 mmHg during diastole, which valve must open during ventricular ejection?
- 4 Explain why the wall of the left ventricle is thicker than the wall of the right ventricle, even though both ventricles pump the same volume of blood per beat.