A white fatty substance that forms a medullary sheath around the axis cylinder of some nerve fibers.

synonyms: myelin, myeline.

Polish: mielina

Lower or hindmost part of the brain; continuous with spinal cord; (`bulb' is an old term for medulla oblongata):
— The medulla oblongata is the most vital part of the brain because it contains centers controlling breathing and heart functioning.

synonyms: bulb, medulla oblongata.

Polish: zamózgowie, rdzeniomózgowie, rdzeń przedłużony

The inner part of an organ or structure in plant or animal.