(mĕ-dŭl′ă, dul′)

pl. medullae [L. medulla, marrow, pith]
SEE: 1. Marrow (1).
2. In anatomy, the innermost or central portion of an organ in contrast to the cortex.
3. The caudal segment of the hindbrain.
SYN: medulla oblongata; bulb (2)
4. The medulla ossium.
medullary (med′ŭl-er″ē, mej″), adj.

adrenal medulla

The central tissue of the adrenal gland. It is filled with pheochromocytes, which are derived from the neural crest and resemble postsynaptic sympathetic ganglion cells. In response to stimulation by presynaptic sympathetic axons, the pheochromocytes secrete epinephrine and norepinephrine into the bloodstream.

SEE: adrenal gland

medulla of hair

The central axis of a hair.

medulla of kidneys

SEE: pyramid, renal

medulla nephrica

SEE: pyramid, renal

medulla oblongata

SEE: Medulla (3).

medulla ossium

Marrow (1).

medulla of ovary

The central portion of the ovary, composed of loose connective tissue, blood vessels, lymphatics, and nerves.

medulla spinalis

The spinal cord.