Neural-Dural Transition at the Thoracic and Lumbar Spinal Nerve Roots: A Histological Study of Human Late-Stage Fetuses

Figure 4

Thoracic and lumbar nerve roots in a fetus with a crown-rump length (CRL) of 245 mm. (a) The left tenth–twelfth thoracic nerves and a radicular artery (RA) and vein with a sheath (arrows) that is continuous with the meningeal layer of the dura (dura). The dorsal root ganglion (DRG) is covered by a thin sheath (stars). (b) and (c) (different sections with a 0.5-mm interval) display RA at the right fifth thoracic nerve level (rt T5): the artery appears not to accompany a protrusion (arrow) of the dura. (d)–(f) (different sections with a 0.5-mm interval) exhibit tortuous courses of the left fourth and fifth thoracic nerve roots. The nerves are surrounded by a continuation of the dura (arrows). All of the panels are shown at the same magnification (scale bar in (a), 1 mm).