[ { "narration": "Welcome to our lesson on the Human Circulatory System! By the end of this section, you will be able to distinguish its major components, describe its main functions, and identify common diseases.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'darkblue'; ctx.font = 'bold 30px Arial'; ctx.textAlign = 'center'; ctx.fillText('The Human Circulatory System', w / 2, h * 0.4); ctx.fillStyle = 'black'; ctx.font = '20px Arial'; ctx.textAlign = 'left'; if (progress > 0.3) ctx.fillText('• Major structural components', w * 0.1, h * 0.6 + (progress - 0.3) * 50); if (progress > 0.6) ctx.fillText('• Main functions', w * 0.1, h * 0.7 + (progress - 0.6) * 50); if (progress > 0.8) ctx.fillText('• Main diseases or disorders', w * 0.1, h * 0.8 + (progress - 0.8) * 50);" }, { "narration": "So, what is a circulatory system? It's the body's transport system, moving essential substances like air, food, minerals, and vitamins, and also carrying away waste materials for removal.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'grey'; ctx.lineWidth = 3; ctx.strokeRect(w * 0.2, h * 0.1, w * 0.6, h * 0.8); ctx.fillStyle = 'green'; ctx.beginPath(); ctx.arc(w * 0.2 + (w * 0.6 * progress), h * 0.3, 10, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w * 0.8 - (w * 0.6 * progress), h * 0.7, 10, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'black'; ctx.font = '16px Arial'; ctx.textAlign = 'center'; ctx.fillText('Nutrients IN', w * 0.2 + (w * 0.6 * progress), h * 0.3 - 20); ctx.fillText('Waste OUT', w * 0.8 - (w * 0.6 * progress), h * 0.7 + 30);" }, { "narration": "The blood flows from the heart to other body parts through a network of blood vessels. The rhythmic contraction and relaxation of the heart muscles pump this vital fluid. Humans have a 'double circulation' system.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w / 2, h / 2, 40 * progress, 0, Math.PI * 2); ctx.fill(); ctx.strokeStyle = 'grey'; ctx.lineWidth = 5; ctx.beginPath(); ctx.moveTo(w / 2, h / 2); ctx.lineTo(w * 0.2, h * 0.2); ctx.lineTo(w * 0.8, h * 0.2); ctx.lineTo(w * 0.5, h * 0.5); ctx.stroke(); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Heart', w / 2, h / 2 + 60); ctx.fillText('Blood Vessels', w / 2, h * 0.1); if (progress > 0.7) ctx.fillText('Double Circulation', w / 2, h * 0.9);" }, { "narration": "The first type is Systematic Circulation, where blood travels between the heart and all other body parts.", "duration": 7, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; ctx.fillRect(w / 2 - 20, h / 2 - 30, 40, 60); ctx.strokeStyle = 'darkgrey'; ctx.lineWidth = 3; ctx.strokeRect(w * 0.1, h * 0.1, w * 0.8, h * 0.8); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Heart', w / 2, h / 2 + 40); ctx.fillText('Body', w / 2, h * 0.95); ctx.strokeStyle = 'red'; ctx.beginPath(); ctx.moveTo(w / 2 + 20, h / 2); ctx.lineTo(w * 0.7, h / 2); ctx.lineTo(w * 0.7, h * 0.7); ctx.lineTo(w / 2, h * 0.7); ctx.stroke(); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w / 2 + 20 + (w * 0.2 * progress), h / 2 + (h * 0.2 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "The second is Pulmonary Circulation, where blood flows specifically between the heart and the lungs.", "duration": 7, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; ctx.fillRect(w / 2 - 20, h / 2 - 30, 40, 60); ctx.strokeStyle = 'darkgrey'; ctx.lineWidth = 3; ctx.strokeRect(w * 0.1, h * 0.1, w * 0.3, h * 0.2); ctx.strokeRect(w * 0.6, h * 0.1, w * 0.3, h * 0.2); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Heart', w / 2, h / 2 + 40); ctx.fillText('Lungs', w * 0.5, h * 0.08); ctx.strokeStyle = 'blue'; ctx.beginPath(); ctx.moveTo(w / 2 - 20, h / 2); ctx.lineTo(w * 0.3, h * 0.15); ctx.stroke(); ctx.fillStyle = 'blue'; ctx.beginPath(); ctx.arc(w / 2 - 20 - (w * 0.2 * progress), h / 2 - (h * 0.2 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "Our circulatory system consists of three main elements: the heart, blood vessels, and blood. Interestingly, the left side of the heart always pumps oxygenated blood, while the right side receives deoxygenated blood.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'lightgrey'; ctx.fillRect(w * 0.1, h * 0.4, w * 0.2, h * 0.2); ctx.fillRect(w * 0.4, h * 0.4, w * 0.2, h * 0.2); ctx.fillRect(w * 0.7, h * 0.4, w * 0.2, h * 0.2); ctx.fillStyle = 'black'; ctx.font = '20px Arial'; ctx.textAlign = 'center'; ctx.fillText('Heart', w * 0.2, h * 0.35); ctx.fillText('Blood Vessels', w * 0.5, h * 0.35); ctx.fillText('Blood', w * 0.8, h * 0.35); ctx.fillStyle = 'red'; ctx.fillRect(w * 0.1, h * 0.6, w * 0.2 * progress, h * 0.05); ctx.fillStyle = 'blue'; ctx.fillRect(w * 0.7, h * 0.6, w * 0.2 * progress, h * 0.05);" }, { "narration": "First, let's look at the heart. It's a muscular, blood-pumping organ made of involuntary cardiac muscle. It has four chambers.", "duration": 9, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; ctx.fillRect(w / 2 - 60, h / 2 - 80, 120, 160); ctx.fillStyle = 'darkred'; ctx.font = '24px Arial'; ctx.textAlign = 'center'; ctx.fillText('Heart Muscle', w / 2, h / 2 - 90); ctx.strokeStyle = 'black'; ctx.lineWidth = 2; ctx.beginPath(); ctx.moveTo(w / 2, h / 2 - 80); ctx.lineTo(w / 2, h / 2 + 80); ctx.moveTo(w / 2 - 60, h / 2); ctx.lineTo(w / 2 + 60, h / 2); ctx.stroke(); ctx.fillStyle = 'white'; ctx.font = '16px Arial'; ctx.fillText('4 Chambers', w / 2, h / 2 + 95);" }, { "narration": "The Right Atrium is an upper chamber that receives deoxygenated blood from the body and pumps it to the right ventricle and then to the lungs. It has a thin wall.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'black'; ctx.lineWidth = 2; ctx.strokeRect(w / 2 - 60, h / 2 - 80, 120, 160); ctx.fillStyle = 'lightblue'; ctx.fillRect(w / 2 - 60, h / 2 - 80, 60 * progress, 80); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Right Atrium', w / 2 - 30, h / 2 - 90); ctx.fillStyle = 'blue'; ctx.beginPath(); ctx.arc(w / 2 - 40, h / 2 - 40 + (80 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "The Left Atrium, also an upper chamber, receives oxygenated blood from the lungs and pumps it to the left ventricle.", "duration": 9, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'black'; ctx.lineWidth = 2; ctx.strokeRect(w / 2 - 60, h / 2 - 80, 120, 160); ctx.fillStyle = 'lightcoral'; ctx.fillRect(w / 2, h / 2 - 80, 60 * progress, 80); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Left Atrium', w / 2 + 30, h / 2 - 90); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w / 2 + 40, h / 2 - 40 + (80 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "The Right Ventricle is a lower chamber that pumps deoxygenated blood to the lungs.", "duration": 7, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'black'; ctx.lineWidth = 2; ctx.strokeRect(w / 2 - 60, h / 2 - 80, 120, 160); ctx.fillStyle = 'lightblue'; ctx.fillRect(w / 2 - 60, h / 2, 60, 80 * progress); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Right Ventricle', w / 2 - 30, h / 2 + 90); ctx.fillStyle = 'blue'; ctx.beginPath(); ctx.arc(w / 2 - 30, h / 2 + 40 - (40 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "The Left Ventricle is the most powerful chamber. It pumps oxygenated blood to the rest of the body, which is why it has much thicker and more muscular walls.", "duration": 10, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'black'; ctx.lineWidth = 2; ctx.strokeRect(w / 2 - 60, h / 2 - 80, 120, 160); ctx.fillStyle = 'lightcoral'; ctx.fillRect(w / 2, h / 2, 60, 80 * progress); ctx.fillStyle = 'darkred'; ctx.fillRect(w / 2 + 50, h / 2, 10 * progress, 80); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Left Ventricle', w / 2 + 30, h / 2 + 90); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w / 2 + 30, h / 2 + 40 - (40 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "Crucially, oxygenated and deoxygenated blood don't mix inside the heart because its chambers are separated by valves. These valves ensure blood flows in only one direction, preventing backflow.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'black'; ctx.lineWidth = 2; ctx.strokeRect(w / 2 - 60, h / 2 - 80, 120, 160); ctx.fillStyle = 'red'; ctx.fillRect(w / 2, h / 2 - 80, 60, 160); ctx.fillStyle = 'blue'; ctx.fillRect(w / 2 - 60, h / 2 - 80, 60, 160); ctx.fillStyle = 'darkgrey'; ctx.fillRect(w / 2 - 5, h / 2 - 5 + (10 * progress), 10, 10); ctx.fillRect(w / 2 - 5, h / 2 - 40 - (10 * progress), 10, 10); ctx.fillStyle = 'white'; ctx.font = '16px Arial'; ctx.textAlign = 'center'; ctx.fillText('Valves', w / 2, h / 2 + 100); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w * 0.7 + (w * 0.1 * progress), h * 0.2, 5, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'blue'; ctx.beginPath(); ctx.arc(w * 0.3 - (w * 0.1 * progress), h * 0.2, 5, 0, Math.PI * 2); ctx.fill();" }, { "narration": "Next, we have blood vessels. These are the pathways for substance transportation. There are three major types of blood vessels.", "duration": 8, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'darkgrey'; ctx.lineWidth = 10; ctx.beginPath(); ctx.moveTo(w * 0.1, h / 2); ctx.lineTo(w * 0.9, h / 2); ctx.stroke(); ctx.lineWidth = 5; ctx.beginPath(); ctx.moveTo(w * 0.1, h / 2); ctx.lineTo(w * 0.1 + (w * 0.8 * progress), h / 2 + 50 * Math.sin(progress * Math.PI * 2)); ctx.stroke(); ctx.fillStyle = 'black'; ctx.font = '24px Arial'; ctx.textAlign = 'center'; ctx.fillText('Blood Vessels', w / 2, h / 2 - 40); ctx.fillText('3 Types', w / 2, h / 2 + 80);" }, { "narration": "First, Arteries. They carry blood away from the heart to different body parts. Arteries have thick, elastic walls. Except for the pulmonary and umbilical arteries, all arteries carry oxygenated blood.", "duration": 13, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'darkred'; ctx.fillRect(w * 0.1, h / 2 - 20, w * 0.8, 40); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w * 0.1 + (w * 0.8 * progress), h / 2, 15, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'black'; ctx.font = '20px Arial'; ctx.textAlign = 'center'; ctx.fillText('Artery (thick wall)', w / 2, h / 2 - 40); ctx.fillStyle = 'blue'; if (progress > 0.7) ctx.fillText('Pulmonary Artery (deoxygenated)', w / 2, h * 0.8);" }, { "narration": "Second, Veins. They return blood back to the heart. Most veins carry deoxygenated blood, except for the pulmonary and umbilical veins.", "duration": 10, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'darkblue'; ctx.fillRect(w * 0.1, h / 2 - 15, w * 0.8, 30); ctx.fillStyle = 'blue'; ctx.beginPath(); ctx.arc(w * 0.9 - (w * 0.8 * progress), h / 2, 12, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'black'; ctx.font = '20px Arial'; ctx.textAlign = 'center'; ctx.fillText('Vein (thinner wall)', w / 2, h / 2 - 40); ctx.fillStyle = 'red'; if (progress > 0.7) ctx.fillText('Pulmonary Vein (oxygenated)', w / 2, h * 0.8);" }, { "narration": "Finally, Capillaries. These tiny, narrow, thin-walled vessels connect arteries and veins, facilitating the exchange of substances with tissues and cells.", "duration": 10, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; ctx.fillRect(w * 0.1, h / 2 - 10, w * 0.2, 20); ctx.fillStyle = 'blue'; ctx.fillRect(w * 0.7, h / 2 - 10, w * 0.2, 20); ctx.strokeStyle = 'darkgrey'; ctx.lineWidth = 2; for (let i = 0; i < 5; i++) { ctx.beginPath(); ctx.moveTo(w * 0.3, h / 2 - 10 + i * 5); ctx.lineTo(w * 0.3 + (w * 0.4 * progress), h / 2 - 10 + i * 5); ctx.stroke(); } ctx.fillStyle = 'green'; ctx.beginPath(); ctx.arc(w * 0.5, h * 0.3 + (h * 0.4 * progress), 7, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Capillaries', w / 2, h / 2 - 40); ctx.fillText('Exchange', w * 0.5, h * 0.7 + (h * 0.1 * progress));" }, { "narration": "Let's trace the path of oxygenated blood: It goes from the lungs, through the pulmonary vein, to the left atrium, then the left ventricle, then out through the aorta, to the body tissues.", "duration": 15, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'lightgrey'; ctx.fillRect(w * 0.1, h * 0.1, w * 0.1, h * 0.1); ctx.fillRect(w * 0.8, h * 0.8, w * 0.1, h * 0.1); ctx.fillStyle = 'red'; ctx.fillRect(w / 2 - 30, h / 2 - 40, 60, 80); ctx.fillStyle = 'black'; ctx.font = '14px Arial'; ctx.textAlign = 'center'; ctx.fillText('Lungs', w * 0.15, h * 0.08); ctx.fillText('Heart', w / 2, h / 2 + 50); ctx.fillText('Body', w * 0.85, h * 0.8); ctx.strokeStyle = 'red'; ctx.lineWidth = 4; ctx.beginPath(); ctx.moveTo(w * 0.15, h * 0.15); ctx.lineTo(w / 2 - 30, h / 2 - 40); ctx.lineTo(w / 2 + 30, h / 2 - 40); ctx.lineTo(w * 0.85, h * 0.85); ctx.stroke(); ctx.fillStyle = 'red'; ctx.beginPath(); ctx.arc(w * 0.15 + (w * 0.7 * progress), h * 0.15 + (h * 0.7 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "And deoxygenated blood: From the body tissues, through the vena cava, to the right atrium, then the right ventricle, and finally through the pulmonary artery back to the lungs.", "duration": 15, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'lightgrey'; ctx.fillRect(w * 0.1, h * 0.1, w * 0.1, h * 0.1); ctx.fillRect(w * 0.8, h * 0.8, w * 0.1, h * 0.1); ctx.fillStyle = 'blue'; ctx.fillRect(w / 2 - 30, h / 2 - 40, 60, 80); ctx.fillStyle = 'black'; ctx.font = '14px Arial'; ctx.textAlign = 'center'; ctx.fillText('Lungs', w * 0.15, h * 0.08); ctx.fillText('Heart', w / 2, h / 2 + 50); ctx.fillText('Body', w * 0.85, h * 0.8); ctx.strokeStyle = 'blue'; ctx.lineWidth = 4; ctx.beginPath(); ctx.moveTo(w * 0.85, h * 0.85); ctx.lineTo(w / 2 + 30, h / 2 + 40); ctx.lineTo(w / 2 - 30, h / 2 + 40); ctx.lineTo(w * 0.15, h * 0.15); ctx.stroke(); ctx.fillStyle = 'blue'; ctx.beginPath(); ctx.arc(w * 0.85 - (w * 0.7 * progress), h * 0.85 - (h * 0.7 * progress), 8, 0, Math.PI * 2); ctx.fill();" }, { "narration": "The third element is Blood itself. This vital fluid tissue transports nutrients, gases, metabolic wastes, and other substances throughout the body. Blood is composed of 45% solid parts and 55% liquid plasma.", "duration": 15, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; ctx.fillRect(w * 0.4, h * 0.3, w * 0.2, h * 0.4 * progress); ctx.fillStyle = 'yellow'; ctx.fillRect(w * 0.4, h * 0.3 + h * 0.4 * progress, w * 0.2, h * 0.55 * progress); ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Blood', w / 2, h * 0.25); if (progress > 0.5) ctx.fillText('45% Solid (Cells)', w / 2, h * 0.75); if (progress > 0.8) ctx.fillText('55% Liquid (Plasma)', w / 2, h * 0.9);" }, { "narration": "The liquid plasma is mostly 90% water, with the remaining 10% being dissolved substances like amino acids and glucose.", "duration": 9, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'lightblue'; ctx.fillRect(w * 0.3, h * 0.2, w * 0.4, h * 0.6); ctx.fillStyle = 'darkblue'; ctx.font = '20px Arial'; ctx.textAlign = 'center'; ctx.fillText('Plasma (90% Water)', w / 2, h * 0.5); ctx.fillStyle = 'green'; ctx.beginPath(); ctx.arc(w * 0.35 + (w * 0.3 * progress), h * 0.3, 10, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'purple'; ctx.beginPath(); ctx.arc(w * 0.65 - (w * 0.3 * progress), h * 0.7, 10, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'black'; ctx.font = '14px Arial'; ctx.fillText('Amino Acids', w * 0.35 + (w * 0.3 * progress), h * 0.3 + 20); ctx.fillText('Glucose', w * 0.65 - (w * 0.3 * progress), h * 0.7 - 20);" }, { "narration": "The solid part of blood is made of three types of cells. First, Red Blood Cells, or Erythrocytes. These disc-shaped, non-nucleated cells are crucial for transporting oxygen and carbon dioxide. They contain hemoglobin, the red pigment that carries oxygen.", "duration": 15, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; for (let i = 0; i < 5; i++) { ctx.beginPath(); ctx.arc(w * 0.2 + i * w * 0.15, h * 0.4 + 20 * Math.sin(progress * Math.PI * 4 + i), 20, 0, Math.PI * 2); ctx.fill(); } ctx.fillStyle = 'darkred'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Red Blood Cells', w / 2, h * 0.3); ctx.fillText('Transport O2/CO2', w / 2, h * 0.7); ctx.fillText('Hemoglobin', w / 2, h * 0.85);" }, { "narration": "Second, White Blood Cells, or Leucocytes. These are colorless, irregularly shaped, and nucleated. Larger than red blood cells, they are the body's defenders, protecting against disease-causing pathogens.", "duration": 13, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'lightgrey'; for (let i = 0; i < 3; i++) { ctx.beginPath(); ctx.arc(w * 0.25 + i * w * 0.25, h * 0.5 + 30 * Math.cos(progress * Math.PI * 3 + i), 25, 0, Math.PI * 2); ctx.fill(); } ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('White Blood Cells', w / 2, h * 0.3); ctx.fillText('Fight Pathogens', w / 2, h * 0.7); ctx.beginPath(); ctx.arc(w * 0.25 + w * 0.25 * progress, h * 0.5, 5, 0, Math.PI * 2); ctx.fill();" }, { "narration": "Third, Platelets, or Thrombocytes. These are small, colorless, non-nucleated biconvex fragments. They are essential for initiating blood clotting when a blood vessel is cut or damaged.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.strokeStyle = 'darkred'; ctx.lineWidth = 5; ctx.beginPath(); ctx.moveTo(w * 0.1, h / 2); ctx.lineTo(w * 0.9, h / 2); ctx.stroke(); ctx.fillStyle = 'lightgrey'; for (let i = 0; i < 7; i++) { ctx.beginPath(); ctx.arc(w * 0.15 + i * w * 0.1, h / 2 + 10 * Math.sin(progress * Math.PI * 2 + i), 8, 0, Math.PI * 2); ctx.fill(); } ctx.fillStyle = 'black'; ctx.font = '18px Arial'; ctx.textAlign = 'center'; ctx.fillText('Platelets', w / 2, h * 0.3); if (progress > 0.5) ctx.fillText('Blood Clotting', w / 2, h * 0.7); ctx.fillRect(w * 0.5 - 20, h / 2 - 10, 40 * progress, 20);" }, { "narration": "Finally, let's briefly touch upon some major diseases and disorders associated with the circulatory system.", "duration": 6, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'darkred'; ctx.font = 'bold 28px Arial'; ctx.textAlign = 'center'; ctx.fillText('Circulatory System Diseases', w / 2, h / 2); ctx.strokeStyle = 'orange'; ctx.lineWidth = 5; if (progress > 0.5) ctx.strokeRect(w / 2 - 150, h / 2 - 40, 300, 80);" }, { "narration": "One common condition is Hypertension, or high blood pressure. It can be caused by factors like age, obesity, high salt consumption, stress, and certain medical conditions.", "duration": 12, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'red'; ctx.fillRect(w * 0.2, h / 2 - 10, w * 0.6, 20 * progress); ctx.fillStyle = 'black'; ctx.font = '24px Arial'; ctx.textAlign = 'center'; ctx.fillText('Hypertension (High Blood Pressure)', w / 2, h * 0.3); ctx.font = '16px Arial'; ctx.textAlign = 'left'; if (progress > 0.4) ctx.fillText('• Age, Obesity', w * 0.1, h * 0.7); if (progress > 0.6) ctx.fillText('• High Salt, Stress', w * 0.1, h * 0.8); if (progress > 0.8) ctx.fillText('• Kidney Problems, Diabetes', w * 0.1, h * 0.9);" }, { "narration": "That concludes our overview of the human circulatory system, its components, functions, and common diseases. Remember, a healthy circulatory system is vital for a healthy body!", "duration": 10, "animation_code": "ctx.clearRect(0, 0, w, h); ctx.fillStyle = 'green'; ctx.beginPath(); ctx.arc(w / 2, h / 2, 80 * progress, 0, Math.PI * 2); ctx.fill(); ctx.fillStyle = 'white'; ctx.font = 'bold 28px Arial'; ctx.textAlign = 'center'; ctx.fillText('Stay Healthy!', w / 2, h / 2); ctx.fillStyle = 'darkgreen'; ctx.font = '18px Arial'; ctx.fillText('Healthy Circulatory System = Healthy Body', w / 2, h * 0.7);" } ]