A medically accurate 3D model of a human heart, shown without excessive blood or gore. The major chambers, arteries, and veins are clearly visible and anatomically correct, with subtle realistic textures in shades of red and crimson, and faint hints of blue or purple for the veins. The model should have a clean, professional look, as if used for a medical or educational reference. Lighting is soft but highlights key details, giving the heart a slightly moist surface.