posterolateral sulcus of spinal cord posterolateral sulcus of spinal cord on either side of the posterior median sulcus of the spinal cord, and at a short distance from it, the posterior nerve roots are attached along a vertical furrow named the posterolateral sulcus. the portion of the medulla spinalis which lies between this and the posterior median sulcus is named the posterior funiculus. posterolateral sulcus of spinal cordspinal cord (dorsolateral sulcus is "s3")detailsidentifierslatinsulcus posterolateralis medullae spinalista98a14.1.02.011ta26055fma75609anatomical terminology