cortex

IPA/ˈkɔːteks/
KK[kˈɔrtɛks]IPA/ˈkɔːrteks/

cortex — noun

  • cortexsingular
  • cortexesplural

1. the outer tissue that covers an organ such as the brain or a kidney; this layer

1.nounC1
Definition

the outer tissue that covers an organ such as the brain or a kidney; this layer carries out specific jobs that the inner part of the organ does not handle.

Example

The prefrontal cortex helps people plan their daily activities and control their impulses.

specific name: prefrontal cortex (planning + impulse control)

When the visual cortex is damaged, a person may struggle to recognise familiar faces.

passive: visual cortex is damaged

Common collocations
  • cerebral cortex
  • prefrontal cortex
  • visual cortex
  • auditory cortex
  • motor cortex
  • sensory cortex
  • renal cortex
  • adrenal cortex
  • cortical layer
  • cortex of the brain
  • cortex of the kidney
Synonyms
  • outer layer

    much broader term; can describe any layered object, not just body organs

  • surface

    refers to the outside boundary of an object rather than a distinct functional tissue layer

Antonyms
  • core

    the innermost part of an organ, opposite in position and usually in function

  • medulla

    the inner tissue of an organ such as the kidney or adrenal gland

Grammar Patterns

the [adjective] cortex

cortex of the [organ]

Usage Note

The plural form is cortices (not 'cortexes'). In medical and scientific writing, this term is almost always preceded by an adjective that names which organ's outer layer is meant — for example, cerebral cortex, prefrontal cortex, renal cortex, or adrenal cortex.

Common Mistakes

The injury affected his cortex.
The injury affected his cerebral cortex.
'Cortex' by itself is vague; specify which organ's outer layer you mean by using the full anatomical name.
The cortex of the brain was examined under a microscope.
The cerebral cortex was examined under a microscope.
'Cerebral cortex' is the standard term in medical English; 'cortex of the brain' sounds like a non-specialist paraphrase.

Word family

  • cortical
    adjectiveC1
  • cortically
    adverbC2

Synonym discussion

Sense: noun/1

Cortex is the most precise term when referring to the functional outer tissue of an organ, especially the brain. 'Outer layer' is a neutral, general phrase that can apply to any layered object — a cake, a planet, or a wall — and lacks the anatomical specificity of cortex. 'Surface' is even broader and suggests only the outermost boundary, not a distinct tissue layer with its own function. 'Rind' and 'shell' typically describe the protective coverings of fruit, eggs, or nuts and are never used for human organs. For example, a neurologist would say 'the auditory cortex processes sound,' not 'the auditory surface' or 'the outer layer of the auditory area.'

outer layersurface ↗rindshell ↗

Common collocations

Nouns

  • brain cortex
  • kidney cortex

Phrases

  • outer layer of the cortex
  • grey matter of the cortex

Prepositions

  • of — cortex of the brain, cortex of the kidney

Etymology

LatinEnglish

Cortex comes directly from Latin cortex, meaning 'bark of a tree' or 'shell'. In the 17th century, anatomists began using the word for the outer layer of the brain because it reminded them of tree bark covering the trunk. Today the term covers the outer tissue of several organs, but the brain remains its most familiar application.