medulla

• 名词，指动物或植物器官或结构的内部部分，如延髓或包裹神经纤维的髓鞘。

A noun referring to the inner part of an organ or structure in animals or plants, such as the medulla oblongata of the brain or the medullary sheath surrounding nerve fibers.

不规则复数

1. White fatty substance around nerve fibersC1formalscientific

   A fatty material that surrounds the core of certain nerve fibers, forming a medullary sheath that aids in the transmission of nerve impulses.

   髓鞘

   • The medulla insulates axons, allowing faster signal transmission.
   • Damage to the medulla can disrupt nerve function.
   • Multiple sclerosis attacks the medulla of nerve fibers.

   同义词medullary sheathmyelinmyelin sheath

2. Medulla oblongata (brainstem)C1formalmedical

   The lower, hindmost part of the brain, which connects to the spinal cord and controls vital autonomic functions such as breathing and heart rate.

   延髓（脑干）

   • The medulla oblongata regulates breathing and blood pressure.
   • An injury to the medulla can be life-threatening.
   • The medulla is essential for maintaining basic life functions.

   同义词medulla oblongatamyelencephalon

3. Inner core of an organ or structureB2formalscientific

   The central or deeper part of an organ or tissue, such as the inner region of a kidney or the pith of a plant stem.

   髓质

   • In plants, the medulla stores nutrients and provides structural support.
   • The renal medulla is responsible for urine concentration.
   • The medulla of the adrenal gland produces stress hormones.

   同义词centercoremarrowpith

   反义词cortex