Cell Mediated Immunity Diagram with Comparative Circulatory Systems

Biological diagram infographic titled "Comparative Circulatory Systems" centered on a clean labeled comparison diagram of two circulatory structures: human double circulation and fish single circulation, shown side-by-side with simplified editorial-grade anatomical cross-sections and flow arrows highlighting blood movement. Create a professional comparison layout for a medical audience, but rendered in a colorful kids-book visual style with cool clinical blues palette, soft cyan and navy accents, selective teal highlights, calm educational mood. Use medical-textbook clarity, editorial scientific illustration, vector-clean lines, no photographic textures. Show 9 labeled components arranged around the central comparison with thin leader lines; each label must include a short heading in English and a one-line function description in English. Include these exact on-image labels and captions: "Human heart" — "Four chambers pump blood through pulmonary and systemic circuits."; "Right ventricle" — "Sends deoxygenated blood to the lungs for gas exchange."; "Left ventricle" — "Drives oxygenated blood to the body at high pressure."; "Pulmonary circuit" — "Carries blood between heart and lungs for oxygen uptake."; "Systemic circuit" — "Delivers oxygen and nutrients to body tissues."; "Fish heart" — "Two main chambers pump blood in a single circuit."; "Gill capillaries" — "Exchange carbon dioxide for oxygen in water flow."; "Systemic capillaries" — "Supply tissues and collect metabolic waste products."; "Single vs double circulation" — "Fish pass blood through one loop; humans use two linked loops." Use directional arrows to distinguish flow paths in both organisms, with oxygenated blood in lighter blue-teal and deoxygenated blood in darker blue for a tasteful clinical schematic. Keep proportions scientifically accurate, labels sharp and readable, balanced whitespace, and a subtle legend style without extra decorative clutter. No gore, no surgical blood, no cruelty imagery, no real patient photographs. All text MUST be written in English (array). Every heading, label, caption, legend and metric name in the image must be in English — not English. Spell each English word correctly using English characters and diacritics. Numbers stay as digits, no graphic gore, no real patient photos, no watermarks No graphic medical gore, no real patient photographs, no surgical blood. For human anatomy, keep illustrations educationally tasteful. For animal anatomy, no cruelty imagery. Scientifically accurate labeling and proportions.