Outside.
Front face: they contain, in the central part, a middle groove which limits with the anterior collateral grooves.
Backface: there's a middle groove that reaches to the central gray substance.
Membrane: the entire spinal cord is cover by the three meninges: dura, arachnoid, and pia mater.
Inside.
Grey substance: is the inner part. In the middle of that, you can find the epididymal duct.
White substance: it's around the grey substance.
