Handwritten infographic explains the human heart's four-chamber pumping system

Handwritten biology infographic on lined notebook page titled “The Human Heart: The Engine That Keeps Life Moving”. Neatly organized physiology study notes with colorful headings, diagrams, charts, and highlights. Heart is a four-chamber muscular organ, fist-sized, pumping ~7,000 L blood/day and ~100,000 beats/day. Central color-coded heart diagram: blue right side deoxygenated (vena cava, right atrium, tricuspid valve, right ventricle, pulmonary artery) and red left side oxygenated (pulmonary veins, left atrium, mitral valve, left ventricle, aorta, septum). Blood flow arrows show body→heart→lungs→heart→body loop. Includes valve notes (tricuspid, mitral, semilunar), cardiac cycle (atrial systole, ventricular systole, diastole) with 60–100 bpm and ~0.8s per beat. Coronary circulation shows heart’s own blood supply and warns blockage causes heart attack. Blood composition pie chart: plasma 55%, formed elements 45% (RBCs oxygen transport, WBCs immunity, platelets clotting). Comparison table contrasts right vs left heart (deoxygenated vs oxygenated, body vs lungs, low vs high pressure). Mnemonic: R returns to lungs, L leaves to body. Exam highlights: myogenic heart, pericardium, septum, aorta, capillaries. Health icons: exercise, diet, sleep, no smoking, stress management. Ends with motivational quote about better life through a healthy heart.