cortex

American  

[kawr-teks] / ˈkɔr tɛks /

noun

cortices, plural cortexes plural

1. Anatomy, Zoology.

   1. the outer region of an organ or structure, as the outer portion of the kidney.

   2. the cerebral cortex.

2. Botany.

   1. the portion of a stem between the epidermis and the vascular tissue; bark.

   2. any outer layer, as rind.

3. Mycology. the surface tissue layer of a fungus or lichen, composed of massed hyphal cells.

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cortex British  

/ ˈkɔːtɛks, ˈkɔːtɪkəl /

noun

1. anatomy the outer layer of any organ or part, such as the grey matter in the brain that covers the cerebrum ( cerebral cortex ) or the outer part of the kidney ( renal cortex )

2. botany

   1. the unspecialized tissue in plant stems and roots between the vascular bundles and the epidermis

   2. the outer layer of a part such as the bark of a stem

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cortex Scientific  

/ kôr′tĕks′ /

1. The outer layer of an organ or body part, such as the cerebrum or the adrenal glands.

2. The region of tissue lying between the epidermis (the outermost layer) and the vascular tissue in the roots and stems of plants. It is composed of collenchyma, parenchyma, and sclerenchyma. In roots the cortex transfers water and minerals from the epidermis to the vascular tissue, which distributes them to other parts of the plant. The cortex also provides structural support and stores food manufactured in the leaves.

3. See illustration at xylem

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Other Word Forms

Derived Forms

• subcortex
  noun
• cortical
  adjective
• cortically
  adverb

Inflected Forms

Nouns

• cortexes
  plural
• cortices
  plural

Etymology

Origin of cortex

1650–60; < Latin: bark, rind, shell, husk

Explanation

The cortex refers to the outer layer of an organ or structure in the body, like the brain, where it plays a crucial role in processing information and thoughts. The cortex in any organ helps to protect it and make sure it functions properly. For example, the brain's cerebral cortex is crucial for high-level functions like memory, attention, thought, and consciousness. However, the term isn't exclusive to the brain; the kidney and adrenal glands also have a cortex essential to their operation. In each case, the cortex plays an important role in maintaining the organ’s overall health.

Example Sentences

See Examples For:

cortex cortexes cortices

At the same time, your brain’s amygdala, or fear and emotion center, calms down and its prefrontal cortex, which governs rational thought, amps up.

From The Wall Street Journal ● Jun. 27, 2026

For many years, scientists believed that attention was controlled primarily by the prefrontal cortex, a brain region that is especially developed in humans and other primates.

From Science Daily ● Jun. 24, 2026

Many animals can also focus their attention despite lacking a highly developed prefrontal cortex.

From Science Daily ● Jun. 24, 2026

When activity in either the auditory cortex or somatosensory cortex was disrupted, participants showed significantly poorer retention of the speech movements they had learned.

From Science Daily ● Jun. 23, 2026

He was struck through the forehead, and the iron must have pierced the frontal lobe of the cortex.

From "Phineas Gage" by John Fleischman

"Both the frontal and posterior temporal cortexes disrupt semantic integration, which we see happen in individuals with various aphasias," Murphy said.

From Science Daily ● Oct. 24, 2023

I think the thing now is the way we are stressed by putting these excessive demands on our very powerful prefrontal cortexes, which I think is more of what makes us human than language.

From Salon ● Dec. 13, 2021

Gallant showed a short video clip to human test subjects and then was able to successfully reconstruct images from that video by observing the brain activity in their visual cortexes.

From New York Times ● Dec. 10, 2021

A select number of Americans, it should be noted, don’t even own a flat-screen, tablet or other instrument of destruction delivering all this rottery into our cerebral cortexes.

From Seattle Times ● Aug. 29, 2021

“In fact, it is one of the largest lateral prefrontal cortexes I’ve ever seen. Yet the orbitofrontal cortex is remarkably small. What do these two facts indicate?”

From "Insurgent" by Veronica Roth

Sensory cortices on the other hand play an important role in how we perceive our environment and make appropriate movements, and how our brains determine what to focus on and what to ignore.

From Science Daily ● Nov. 21, 2024

In fact, neuroimaging studies show the brains of children who eat more processed snack foods are smaller in volume, particularly in the frontal cortices, than those of children who eat a more healthful diet.

From Salon ● May 28, 2024

When activity in sensory cortices exceeds a threshold, a global ignition event is triggered across these cortical areas, whereby information is sent to the entire workspace.

From Scientific American ● Sep. 8, 2023

In one 2022 study, Fani, Harnett and their colleagues reported that among 81 Black women who had experienced trauma, those who reported experiencing more racial discrimination showed proportionally thinner gray matter in the cingulate cortices.

From Washington Post ● Feb. 16, 2023

Do the cortices not enter into lamentatory conversation, taking the impress of exteriorities?

From "The Astonishing Life of Octavian Nothing, Traitor to the Nation, Volume I: The Pox Party" by M.T. Anderson