A section through the aortic bifurcation and the bladder portion of the urogenital sinus.
Observe:
1. The dilation on the herniated caudal limb of the midgut that represents the cecum.
2. The umbilical arteries and allantois entering the umbilical cord.
3. The mesonephric duct coursing toward the urogenital sinus.
4. The caudal edge of the junction between the duodenum and midgut loop.
5. The iliac lymph sac around the external iliac vessels.
Keywords: L-2 spinal ganglion, allantois, aortic bifurcation, cecum (caudal limb of midgut), cranial limb of midgut, edge of duodenum and midgut loop, edge of foot, external iliac artery, external iliac vein, ganglion cells, hindgut, iliac lymph sac, iliopsoas muscle group, inferior mesenteric vessels, inferior vena cava (supracardinal segment), left umbilical artery, mesonephric duct, mesonephros, metanephric duct, metanephros, neural canal, right umbilical artery, superior mesenteric artery and vein, umbilical cord, umbilical vein, urogenital sinus (bladder portion), vitelline (omphalomesenteric) vein
Source: Atlas of Human Embryos.