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Longman Dictionary of Contemporary English
▪ Hydrocortisone is produced by the adrenal cortex.
▪ With the collapsed lung and the damaged cerebral cortex?
▪ But even if the totals were constant across individuals, the subtotals would still vary between different parts of the cerebral cortex.
▪ The implications of differences in cortical organization go beyond our understanding of the cerebral cortex.
▪ The major growth of cerebral cortex, as our ancestors became fancier and fancier primates, was sideways.
▪ The information fed directly into Jonathan's cerebral cortex.
▪ Does a smart person have more cerebral cortex than an idiot?
▪ For example, since all mammals have a cerebral cortex we must assume that the ancestral form also had one.
▪ That seems to activate the cerebral cortex in the parietal lobes more than in the frontal lobes.
▪ Indeed, it is extremely difficult to distinguish between the primary visual cortex and surrounding areas in this species.
▪ Yet back in the primary visual cortex, the fourth layer is the most impressive of all.
▪ The strongest evidence for such a contribution comes from studying the effects of removal of the primary visual cortex.
▪ Part of the problem is that they are often on tasks that are also severely impaired after destruction of primary visual cortex.
▪ Matters are further complicated by the fact that information from the two eyes is brought together in the primary visual cortex.
▪ You find that cells in adjacent parts of the visual cortex are activated by stimulation in adjacent parts of the visual field.
▪ In the case of the visual cortex, no one knows yet.
▪ It can also influence learned and voluntary reactions to visual stimuli when the visual cortex is absent.
▪ But for the visual cortex, light flashes work pretty well.
▪ Indeed, it is extremely difficult to distinguish between the primary visual cortex and surrounding areas in this species.
▪ Yet back in the primary visual cortex, the fourth layer is the most impressive of all.
▪ What is their relationship to the visual cortex?
▪ For example, our visual system maps visual space on to the surface of our visual cortex.
▪ The eyes transmit electrical signals to the visual cortex in the brain.
▪ But even if the totals were constant across individuals, the subtotals would still vary between different parts of the cerebral cortex.
▪ Interestingly, this is also true of mammals from which the auditory cortex has been removed.
▪ Rats have less than a square inch of cortex, less than humans by a factor of 500.
▪ The major growth of cerebral cortex, as our ancestors became fancier and fancier primates, was sideways.
▪ The next level of control is the upper motor neuron with cells of origin in the sensorimotor cortex.
▪ The normal stabilising mechanisms are out of control and the whole cortex becomes involved.
▪ With the collapsed lung and the damaged cerebral cortex?
The Collaborative International Dictionary

Cortex \Cor"tex\ (k[^o]r"t[e^]ks), n.; pl. Cortices (-t?-s?z).

  1. Bark, as of a tree; hence, an outer covering.

  2. (Med.) Bark; rind; specifically, cinchona bark.

  3. (Anat.) The outer or superficial part of an organ; as, the cortex or gray exterior substance of the brain.

Douglas Harper's Etymology Dictionary

1650s, "outer shell, husk," from Latin cortex "bark of a tree" (see corium). Specifically of the brain, first recorded 1741.


n. 1 (context countable anatomy English) The outer layer of an internal organ or body structure, such as the kidney or the brain. 2 (context uncountable botany English) The tissue of a stem or root that lies inward from the epidermis, but exterior to the vascular tissue.

  1. n. the layer of unmyelinated neurons (the gray matter) forming the cortex of the cerebrum [syn: cerebral cortex, cerebral mantle, pallium]

  2. the tissue forming the outer layer of an organ or structure in plant or animal [ant: medulla]

  3. [also: cortices (pl)]


Cortex may refer to:

Cortex (anatomy)

In anatomy and zoology, the cortex ( Latin for bark, rind, shell or husk) is the outermost (or superficial) layer of an organ. Organs with well-defined cortical layers include kidneys, adrenal glands, ovaries, the thymus, and portions of the brain, including the cerebral cortex, the best-known of all cortices.

Cortex (hair)

The cortex of the hair shaft is located between the hair cuticle and medulla and is the thickest hair layer. It also contains most of the hair's pigment, giving the hair its color. The pigment in the cortex is melanin, which is also found in skin. The distribution of this pigment varies from animal to animal and person to person. In humans, the melanin is primarily denser nearer the cuticle whereas in animals, melanin is primarily denser nearer the medulla.

Cortex (journal)

Cortex is a scientific journal published semimonthly by Elsevier. It is devoted to the study of "cognition and of the relationship between the nervous system and mental processes". The journal was founded in 1964 and is currently edited by Sergio Della Sala.

Cortex (botany)

A cortex is the outermost layer of a stem or root in a plant, or the surface layer or "skin" of the nonfruiting part of the body of some lichens.

In botany, the cortex is the outermost layer of the stem or root of a plant, bounded on the outside by the epidermis and on the inside by the endodermis. In plants, it is composed mostly of differentiated cells, usually large thin-walled parenchyma cells of the ground tissue system. The outer cortical cells often acquire irregularly thickened cell walls, and are called collenchyma cells. Some of the outer cortical cells may contain chloroplasts. It is responsible for the transportation of materials into the central cylinder of the root through diffusion and may also be used for food storage in the form of starch.

On a lichen, the cortex is the " skin", or outer layer of thallus tissue that covers the undifferentiated cells of the medulla. Fruticose lichens have one cortex encircling the branches, even flattened, leaf-like forms; foliose lichens have different upper and lower cortices; crustose, placodioid and squamulose lichens have an upper cortex but no lower cortex; and leprose lichens lack any cortex.

Cortex (archaeology)

In lithic analysis in archaeology the cortex is the outer layer of rock formed on the exterior of raw materials by chemical and mechanical weathering processes. It is often recorded on the dorsal surface of flakes using a three class system: primary, secondary, and tertiary. The amount of cortex present on artifacts in an archaeological assemblage may indicate the extent of lithic reduction that has occurred. Primary, secondary, and tertiary designations for flakes are generally determined by relative amounts of cortex presented on the dorsal surface. Some archaeologists classify flakes with no cortex as tertiary, flakes with some cortex as secondary, and flakes with all cortex as primary, whereas others may distinctions at every third or half of the dorsal surface covered. Differences in how archaeologists classify the amount of cortex and the results of experimental archaeological tests demonstrating moderate correlation between amount of cortex and stage of reduction, have limited the validity of assumptions based on amount of cortex solely.

Usage examples of "cortex".

The Babinski reflex - the great toe pulling up instead of curling down - was a grave, grave sign that her cerebral cortex, the thinking part of her brain, was no longer influencing the movements of her body.

Because the tract connects the cortex and the spinal cord it is also called the corticospinal tract.

All the structure of the brain from the cerebral cortex down to the hypothalamus is developed from the forebrain of the original fishy ancestor of the vertebrates.

Beneath the membranes, the gyri and folds of the cerebral cortex were plainly visible, traced with darker arteries and veins.

The ridge was still rough and wavy when the cortex was removed, and he put the hammerstone down to pick up a solid length of antler that had been cut off below the first fork to eliminate all branches.

Jondalar picked up his hammerstone, an oval stone, dented and chipped from use, that fit comfortably in his hand, and began knocking off the balance of the chalky cortex in preparation for working it.

His exoself responded to the command, spinning his balls into hyperspheres, rebuilding his retinas as four- dimensional arrays, rewiring his visual cortex, boosting his neural model of the space around him to encompass five dimensions.

On the other hand, if the cortex is unusually stimulated, the failure of the hypothalamic signals may be insufficient to induce sleep.

When, however, the stimulus reaches a higher centre in the cortex of the brain, the mind becomes conscious, or interprets the impression, and any resulting action will be controlled by consciousness, through impulses given to the motor nerves.

Sensation Produced By Intracortical Microstimulation Of The Human Occipital Cortex.

Of A Visual Prosthesis For The Blind Based On Intracortical Microstimulation Of The Visual Cortex.

Some students of human evolution believe that part of the selection pressure behind this enormous burst in brain evolution was in the motor cortex and not at first in the neocortical regions responsible for cognitive processes.

Laboratory of Neurophysiology, and over the next half dozen years he methodically created the first detailed map of the functional anatomy of the cortex.

The first type of calibration would involve the human ear, nervous system and auditory cortex all being pre-programmed to grow and develop in such a way that the intervals between different pairs of pitch values whose frequencies are in the same ratios are perceived as the same intervals.

Therefore, although the reptilian cerebrum is still mainly concerned with the analysis of smell and taste sensations, it is larger, and in the part of the cerebral cortex nearest the front end there is the development of something new.