Digestive tract — enzymes and where absorption happens

{
  "nodes": [
    { "id": "mouth", "type": "funnel", "label": "Mouth — salivary amylase at pH 6.8", "x": 40, "y": 40, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#b45309", "bold": true },
    { "id": "oesophagus", "type": "cylinder-h", "label": "Oesophagus — peristalsis in about 8 s", "x": 215, "y": 40, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#b45309" },
    { "id": "stomach", "type": "cylinder", "label": "Stomach — pH 1.5 to 3.5, pepsin, 2–4 h", "x": 390, "y": 40, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d", "bold": true },
    { "id": "duodenum", "type": "cylinder-h", "label": "Duodenum — iron and calcium absorbed", "x": 565, "y": 40, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d", "bold": true },
    { "id": "jejunum", "type": "cylinder-h", "label": "Jejunum — sugars, amino acids, most fat", "x": 740, "y": 40, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d", "bold": true },
    { "id": "ileum", "type": "cylinder-h", "label": "Ileum — bile salts and vitamin B₁₂", "x": 915, "y": 40, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d", "bold": true },
    { "id": "chewing", "type": "gear", "label": "Chewing raises the surface for enzymes", "x": 40, "y": 200, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#b45309" },
    { "id": "parietal", "type": "test-tube", "label": "Parietal cells make HCl and intrinsic factor", "x": 215, "y": 200, "width": 150, "height": 104, "fill": "#e0f2fe", "stroke": "#0369a1", "bold": true },
    { "id": "chyme", "type": "water-drop", "label": "Chyme released through the pylorus", "x": 390, "y": 200, "width": 150, "height": 104, "fill": "#dbeafe", "stroke": "#1d4ed8" },
    { "id": "pancreas", "type": "petri-dish", "label": "Pancreas — 1.5 L of juice with HCO₃⁻", "x": 565, "y": 200, "width": 150, "height": 104, "fill": "#e0f2fe", "stroke": "#0369a1", "bold": true },
    { "id": "villi", "type": "honeycomb", "label": "Villi and microvilli — 30 m² of surface", "x": 740, "y": 200, "width": 150, "height": 104, "fill": "#e0f2fe", "stroke": "#0369a1", "bold": true },
    { "id": "lacteal", "type": "network-globe", "label": "Lacteals carry chylomicrons to the lymph", "x": 915, "y": 200, "width": 150, "height": 104, "fill": "#fce7f3", "stroke": "#be185d", "bold": true },
    { "id": "bile", "type": "bottle", "label": "Liver and gallbladder — 600 mL of bile", "x": 40, "y": 360, "width": 150, "height": 104, "fill": "#e0f2fe", "stroke": "#0369a1", "bold": true },
    { "id": "emulsify", "type": "sphere", "label": "Bile salts emulsify fat into micelles", "x": 215, "y": 360, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#b45309", "bold": true },
    { "id": "enzymes", "type": "gear", "label": "Trypsin, lipase and amylase work at pH 8", "x": 390, "y": 360, "width": 150, "height": 104, "fill": "#fef3c7", "stroke": "#b45309", "bold": true },
    { "id": "portal", "type": "arrow-right", "label": "Hepatic portal vein — first stop, the liver", "x": 565, "y": 360, "width": 150, "height": 104, "fill": "#fce7f3", "stroke": "#be185d", "bold": true },
    { "id": "colon", "type": "cylinder-h", "label": "Colon — water and Na⁺, 12 to 48 h", "x": 740, "y": 360, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d", "bold": true },
    { "id": "microbiota", "type": "petri-dish", "label": "Colonic microbiota ferment fibre to SCFA", "x": 915, "y": 360, "width": 150, "height": 104, "fill": "#dcfce7", "stroke": "#15803d", "bold": true },
    { "id": "water", "type": "gauge-chart", "label": "9 L of fluid a day in, under 200 mL out", "x": 390, "y": 520, "width": 150, "height": 104, "fill": "#ccfbf1", "stroke": "#0f766e", "bold": true },
    { "id": "faeces", "type": "bucket", "label": "Faeces — about 150 g, a third bacteria", "x": 740, "y": 520, "width": 150, "height": 104, "fill": "#fce7f3", "stroke": "#be185d" }
  ],
  "edges": [
    { "id": "e1", "source": "chewing", "target": "mouth", "style": "dashed" },
    { "id": "e2", "source": "mouth", "target": "oesophagus", "thickness": 2.5 },
    { "id": "e3", "source": "oesophagus", "target": "stomach", "thickness": 2.5 },
    { "id": "e4", "source": "parietal", "target": "stomach", "label": "acid denatures and activates pepsin", "style": "dashed" },
    { "id": "e5", "source": "stomach", "target": "chyme" },
    { "id": "e6", "source": "chyme", "target": "duodenum", "thickness": 2.5 },
    { "id": "e7", "source": "pancreas", "target": "duodenum", "label": "HCO₃⁻ neutralises the acid", "thickness": 2.5 },
    { "id": "e8", "source": "pancreas", "target": "enzymes" },
    { "id": "e9", "source": "bile", "target": "duodenum" },
    { "id": "e10", "source": "bile", "target": "emulsify", "thickness": 2.5 },
    { "id": "e11", "source": "emulsify", "target": "jejunum", "label": "micelles present the fat to the villi" },
    { "id": "e12", "source": "enzymes", "target": "jejunum", "label": "digestion finishes on the brush border", "style": "dashed" },
    { "id": "e13", "source": "duodenum", "target": "jejunum", "thickness": 2.5 },
    { "id": "e14", "source": "jejunum", "target": "ileum", "thickness": 2.5 },
    { "id": "e15", "source": "villi", "target": "jejunum", "style": "dashed" },
    { "id": "e16", "source": "jejunum", "target": "portal", "label": "sugars and amino acids", "thickness": 2.5 },
    { "id": "e17", "source": "jejunum", "target": "lacteal", "label": "fat leaves as chylomicrons", "thickness": 2.5 },
    { "id": "e18", "source": "ileum", "target": "bile", "label": "95% of bile salts recycled" },
    { "id": "e19", "source": "ileum", "target": "colon", "thickness": 2.5 },
    { "id": "e20", "source": "colon", "target": "microbiota" },
    { "id": "e21", "source": "colon", "target": "water", "style": "dashed" },
    { "id": "e22", "source": "colon", "target": "faeces", "thickness": 2.5 },
    { "id": "e23", "source": "microbiota", "target": "faeces", "label": "and vitamin K on the way out" }
  ]
}