The Heart in 3D
A muscular organ that pumps blood through a double circulation — keeping oxygenated and deoxygenated blood completely separate. Rotate it, zoom in, and tap each labelled part to learn its structure and function the NCERT way.
Parts of the heart
Aorta
Largest artery; carries oxygenated blood from the left ventricle to the whole body.
Left atrium
Receives oxygenated blood from the lungs through the pulmonary veins.
Right atrium
Receives deoxygenated blood from the body through the venae cavae.
Left ventricle
Thickest chamber; pumps oxygenated blood into the aorta at high pressure.
Right ventricle
Pumps deoxygenated blood into the pulmonary artery to reach the lungs.
Bicuspid (mitral) valve
Two-flap valve between the left atrium and ventricle; stops backflow.
Heart — the NCERT essentials
NCERT — Body Fluids and Circulation. The human heart has four chambers: two thin-walled atria above and two thick-walled ventricles below. The left ventricle has the thickest wall because it pumps blood to the whole body.
Deoxygenated blood from the body enters the right atrium via the venae cavae, moves to the right ventricle, and is pumped to the lungs. Oxygenated blood returns from the lungs to the left atrium, passes to the left ventricle, and is pumped into the aorta. Because blood passes through the heart twice in one cycle, this is called double circulation.
The heart is myogenic: the sino-atrial (SA) node acts as the pacemaker, and valves (tricuspid on the right, bicuspid/mitral on the left) prevent backflow, producing the 'lub–dub' heart sounds.
Did you know? It is enclosed in a double membrane, the pericardium, with pericardial fluid that reduces friction.
How the heart works — step by step
- 1
Joint diastole: all chambers relax; blood flows from atria into ventricles.
- 2
Atrial systole: the SA node fires and both atria contract, topping up the ventricles.
- 3
Ventricular systole: ventricles contract; AV valves shut ('lub') and blood is forced into the aorta and pulmonary artery.
- 4
Ventricular diastole: ventricles relax; semilunar valves shut ('dub') to stop backflow, and the cycle repeats.
FAQ
Heart — frequently asked questions
What is the function of the heart?▾
Pumps blood through double circulation. The heart is myogenic — the SA node (pacemaker) sets the rhythm on its own.
What are the main parts of the heart?▾
Key labelled parts include Aorta, Left atrium, Right atrium, Left ventricle, Right ventricle, Bicuspid (mitral) valve. In the 3D model you can tap each one to read what it does.
Which NCERT chapter covers the heart for NEET?▾
NCERT — Body Fluids and Circulation. The human heart has four chambers: two thin-walled atria above and two thick-walled ventricles below. The left ventricle has the thickest wall because it pumps blood to the whole body.
Is there an interactive 3D heart model for NEET students?▾
Yes. PracticeNEET's 3D Anatomy Studio lets you rotate and zoom a real heart model and tap labelled dots to learn each part — free, in your browser, no sign-in needed to explore.
See the heart from every angle.
Open the interactive 3D model — rotate, zoom, and tap each labelled part.
Open the 3D Anatomy Studio