Medulla in general means the inner part, and derives from the Latin word for 'marrow'.

In medicine it is contrasted to the cortex. Examples of its use include:

• the medulla oblongata, a part of the brain stem
• the renal medulla, a part of the kidney
• the adrenal medulla, a part of the adrenal gland
• medulla spinalis, another term for spinal cord