medulla
/mɛˈdʌlə
/noun Anatomy
1The inner region of an organ or tissue, especially when it is distinct from the outer region or cortex (as in a kidney, an adrenal gland, or hair): the adrenal medulla produces adrenaline...
- The adrenal cortex is of mesodermal origin, whereas the adrenal medulla is derived from the neural crest.
- The biopsy specimen consisted of renal cortex and outer medulla and contained 17 glomeruli.
- The nodules did not invade the adrenal capsule or adrenal medulla.
1.1 short for medulla oblongata.The brainstem consists of the midbrain, pons and medulla, structures located deep in the back of the brain....
- Similar changes may be seen in the medulla and upper brain stem.
- Removal of the meninges and some cranial nerve roots allow salient features of the ventral or anterior aspect of the medulla and pons to be examined more easily.
1.2 [mass noun] Botany The soft internal tissue or pith of a plant: the main bulk of the potato tuber is pith or medulla...
- Chloroplasts were abundant in the secondary cortex and secondary phloem, and occurred throughout the secondary xylem rays and medulla of 3-year-old stems.
Derivatives
medullary
/ adjective ...- Radiologic examination in all cases except one revealed a well-circumscribed mass in the hilar and medullary region of the kidney.
- On the right is seen the large, medullary area of the cerebral hemisphere, surrounded by a layer of gray cortical matter.
- In all reported cases of renal medullary carcinoma in which the race was known, the patients have been black.
Origin
Late Middle English (in the sense 'bone marrow'): from Latin, 'pith or marrow'.