Heart and great vessels
The heart is a four-chambered muscular pump. Systemic venous blood reaches the right heart; pulmonary venous blood reaches the left heart. Valves maintain predominantly one-way flow.
Open interactive lesson & self-check ↗Four-chamber blood flow
Original conceptual SVG · scalableBlue arrows = relatively oxygen-poor blood; coral arrows = relatively oxygen-rich blood. Schematic flow; anatomy and dimensions are not to scale.
Orient the chambers
The right atrium receives blood through the venae cavae. The right ventricle ejects through the pulmonary trunk. Pulmonary veins enter the left atrium; the left ventricle ejects through the aorta.
Map the four valves
Tricuspid: right atrium to right ventricle. Pulmonary: right ventricle to pulmonary trunk. Mitral: left atrium to left ventricle. Aortic: left ventricle to aorta.
Think anatomically
The interventricular septum separates the ventricles. The left ventricular wall is normally thicker because it pumps against systemic vascular resistance.
Reference and next reading
Explore the original curriculum and publisher-hosted resources for full-depth reading; this note is an original schematic introduction, not an exhaustive chapter.