Just like cerebral cortex,, is cerebral medulla also a part of cerebrum or is it a part medulla oblongata

Solution:

Our brain is divided into Cerebrum, Cerebellum, and Brain stem. The brain stem is further divided into Midbrain, Pons, and Medulla Oblongata. Medulla is the lowest part of brain stem. Medulla is also known as Cerebral Medulla. The Medulla controls autonomic activities like respiration and heartbeat by transmission of signals between brain and spinal cord.   

So, we can say that cerebral medulla is not a part of cerebrum but is actually medulla oblongata.