3D Human HeartAnatomy, valves & blood flow. 3D Kidney FunctionFull cutaway, nephron to ureter. 3D Human LiverLobes, portal triad & bile duct. The Learning Brain15 structures, how a skill sticks. 3D Human Eye15 structures, light to signal. 3D Human Lungs15 structures, breath to bloodstream. 3D Human DNA8 structures, backbone to bases. Inside a Human CellYou're viewing this model now. The Nucleus4 zoom levels, whole nucleus to a base pair. Neural Brain46 neurons, live signal traffic. Mitosis & Meiosis3D spindle, prophase to cytokinesis. Enzyme Active SiteFold a chain, dock a substrate, watch it react. Cell MembraneFluid mosaic & the Na⁺/K⁺ pump. The NephronFiltration to urine, one loop of Henle at a time. Gas ExchangeAlveolus, capillary & the O₂-hemoglobin curve. Cardiac Conduction SystemSA node to Purkinje fibres, synced to a live ECG. Protein SynthesisDNA to folded peptide, codon by codon. DNA Replication ForkLeading vs lagging, Okazaki fragment by fragment. The SynapseVesicle to receptor, one impulse across the cleft. SNARE Vesicle FusionFour helices zip two membranes into one. ATP SynthaseProtons spin a turbine that makes ATP.