Mermaid Flowchart: Double Circulation

Key Exception Points

• Pulmonary ARTERIES = deoxygenated blood (exception to artery rule)
• Pulmonary VEINS = oxygenated blood (exception to vein rule)
• Left ventricle has the THICKEST wall (systemic circuit requires highest pressure ~120 mmHg)
• Right ventricle pumps only at ~25 mmHg (pulmonary circuit has lower resistance)