Question

What the medulla lies beneath

Answer 1

Do you mean medulla oblongata

Then the answer is pons varolli

I hope this helps (θ‿θ)

Answer 2

Answer:

The base of the medulla is defined by the commissural fibers; crossing over from the ipsilateral side in the spinal cord to the contralateral side in the brain stem. Below this lies the spinal cord. The medulla oblongata controls autonomic functions and relays nerve signals between the brain and spinal cord.