A section through the terminal ventricle of the central canal.
Observe:
1. The two derivatives of the ectomeninx: the chondrogenic layer and dura mater separated by a venous plexus.
2. The junction of the primitive filum terminale with the spinal cord.
Keywords: S-4 dorsal root, central canal, chondrogenic layer, dura mater, gluteus maximus muscle, junction of primitive filum terminale and spinal cord, primitive filum terminale, sacral neural arches (S-4 and S-5), terminal ventricle of spinal cord, venous plexus(es)
Source: Atlas of Human Embryos.