Fig. 7

A Carnegie stage 18 human embryo (week 7, 13–17 mm CRL). Frontal section showing the jugular lymph sac (L) adjacent to the jugular vein (V) and the carotid artery (A). Also visible are: Oe–oesophagus; S–spinal nerve; T–trachea; VB–vertebral body. We are grateful to Prof. S. Yamada for giving us the opportunity to photograph the specimen at the Kyoto human embryology collection. Bar = 300 µm B Schematic of a human embryo corresponding to approx. 30 mm CRL showing the localization of the main anlagen of the lymphatic vascular system. 1: cranial cardinal vein (internal jugular vein); 2: Jugulo-axillary lymphatic plexus (lymph sac); 3: caudal cardinal vein; 4: Aorta; 5: Diaphragm; 6: Thoracic duct (paired); 7: Superior mesenteric artery; 8: Cisterna chyli; 9: Mesenteric (retroperitoneal) lymph sac; 10: Lumbar lymph plexus; 11: Iliac lymph plexus (10 and 11 collectively called posterior lymph sac); 12: Aortic bifurcation. Drawing based on a schematic by B. von Gaudecker; p355 in: [215]