medulla

/medˈʌl.ə/ (bre, ipa) · /məˈdʌl.ə/ (ame, ipa) · /mə-ˈdə-lə/ (ame, mw)

medulla — noun

  • medullasingular
  • medullasplural

1. the soft material deep inside an organ, gland, or body structure — for example,

1.名詞C2
釋義

the soft material deep inside an organ, gland, or body structure — for example, the inner part of a kidney or the centre of an adrenal gland

例句

The scan revealed a small growth inside the medulla of her right kidney.

collocation: medulla of [organ]

Dr. Okonkwo pointed to the adrenal medulla on the screen during the lecture.

同義詞
  • core

    everyday term for the centre of any object; medulla is specifically anatomical

  • interior tissue

    a descriptive phrase, not a standard anatomical term like medulla

  • deep structure

    used in imaging reports but less precise than medulla

反義詞
  • cortex

    the outer layer of an organ, paired with medulla in anatomy (e.g. adrenal cortex vs adrenal medulla)

用法筆記

Distinguish from sense 2 (BRAINSTEM CENTRE) and sense 3 (NERVE COATING). This is the general anatomical meaning: the deep inner tissue found in any organ or gland, always positioned beneath an outer layer.

常見錯誤

The outer medulla of the adrenal gland releases hormones.
The inner medulla of the adrenal gland releases hormones; the outer cortex releases different ones.
💡medulla always refers to the inner part, never the outer layer of an organ.

2. the lowest part of the brain, where it joins the spinal cord, that runs automati

2.名詞C2
釋義

the lowest part of the brain, where it joins the spinal cord, that runs automatic body functions such as breathing, heartbeat, and swallowing without any conscious effort

例句

The medulla keeps the heart beating and the lungs working even during deep sleep.

automatic functions: breathing and heartbeat

Nurse Ishikawa explained that a damaged medulla can stop a person from breathing on their own.

同義詞
  • medulla oblongata

    the full anatomical term; 'medulla' is the everyday shortening used by doctors

  • brainstem base

    descriptive but not a standard term in medical textbooks

用法筆記

The full term is 'medulla oblongata,' but doctors and textbooks often shorten it to just 'medulla.' Damage to this area is extremely dangerous because it controls vital functions. Distinguish from sense 1 (DEEP ORGAN TISSUE), which can refer to any organ's inner layer.

常見錯誤

The kidney's medulla controls breathing.
The medulla oblongata controls breathing; the renal medulla is the inner part of the kidney.
💡the word 'medulla' alone changes meaning depending on which body part it refers to.

3. a layer of white fatty material that wraps around certain nerve fibres, like the

3.名詞C2
釋義

a layer of white fatty material that wraps around certain nerve fibres, like the plastic coating around an electrical wire, so that signals can travel along the nerve quickly and without interference

例句

The medulla around the nerve fibre acts like the plastic coating on a copper wire.

analogy: insulation around an electrical wire

When the medulla breaks down, nerve signals slow and muscles begin to weaken or twitch.

同義詞
  • myelin sheath

    the standard modern term; 'medulla' in this sense is older and mostly historical

  • medullary sheath

    the full form of this sense; 'medulla' is the shortened version

用法筆記

This sense appears most often in the phrase 'medullary sheath.' In modern medical English, 'myelin sheath' is the more common term for the same structure. Distinguish from sense 1 (DEEP ORGAN TISSUE) and sense 2 (BRAINSTEM CENTRE).

常見錯誤

The medulla oblongata wraps around nerve fibres.
The medulla (myelin sheath) wraps around nerve fibres; the medulla oblongata is part of the brain.
💡sense 2 and sense 3 are completely different structures.