cortex


cortex
/kawr"teks/, n., pl. cortices /-teuh seez'/.
1. Anat., Zool.
a. the outer region of an organ or structure, as the outer portion of the kidney.
b. the cerebral cortex.
2. Bot.
a. the portion of a stem between the epidermis and the vascular tissue; bark.
b. any outer layer, as rind.
3. Mycol. the surface tissue layer of a fungus or lichen, composed of massed hyphal cells.
[1650-60; < L: bark, rind, shell, husk]

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In plants, the tissue of unspecialized cells lying between the epidermis (surface cells) and the vascular, or conducting, tissues (see phloem and xylem) of stems and roots.

Cortical cells may contain stored food or other substances, such as resins, latex, essential oils, and tannins. Cortical cells in herbaceous stems, young woody stems, and stems of succulents contain chloroplasts and can therefore make food by photosynthesis. Food, usually in the form of starch, in edible roots, bulbs, and tubers is stored mostly in the cortex.

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▪ plant tissue
      in plants, tissue of unspecialized cells lying between the epidermis (surface cells) and the vascular, or conducting, tissues of stems and roots. Cortical cells may contain stored carbohydrates or other substances such as resins, latex, essential oils, and tannins. In roots and in some herbaceous stems but not usually in woody stems, the innermost layer of cortical cells is differentiated into a cell layer called the endodermis. The cell walls of the endodermis possess a woody and corky band, called the casparian strip, around all the cell walls except those facing toward the axis and the surface of the root or stem. The endodermis with its casparian strips may function in regulating the flow of water between outer tissues and the vascular cylinder at the centre of the root. Within an inch or two of shoot tips, some flowering plants have a starch sheath (a layer of cells with much stored starch) in the same position as an endodermis.

      The cortex often develops into a type of tissue called aerenchyma, which contains air spaces produced by separation, tearing, or dissolution of the cortex cell walls. Cortical cells in herbaceous stems, young woody stems, and stems of succulents (cacti and other fleshy plants) contain chloroplasts and can therefore convert carbon dioxide and water to simple carbohydrates (carbohydrate) (carbon fixation) using photosynthesis. Simple carbohydrates may then be metabolized into complex carbohydrates such as starch, which is stored in the cortex in edible roots, bulbs, and tubers.

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Universalium. 2010.

Look at other dictionaries:

  • Cortex — (Latin: bark , rind , shell or husk ) may refer to: Contents 1 Sciences 2 Anatomy 2.1 Organs 2.1.1 The brain 3 …   Wikipedia

  • cortex — [ kɔrtɛks ] n. m. • 1896; mot lat. « écorce » 1 ♦ Anat. Partie externe périphérique. Cortex cérébral, rénal. Absolt Le cortex : l écorce cérébrale. ⇒ cortical; aussi néocortex. Cortex surrénal. ⇒ corticosurrénale. 2 ♦ Biol. Tissu externe primaire …   Encyclopédie Universelle

  • cortex — CÓRTEX, cortexuri, s.n. 1. Scoarţă a unui copac. ♦ Coajă a unui fruct. 2. Înveliş al părului, cuprins între măduva centrală şi cuticula exterioară. 3. (În sintagmele) Cortex cerebral = scoarţa cerebrală. Cortex suprarenal = partea periferică a… …   Dicționar Român

  • Cortex — (lat. für ‚Rinde‘, ‚Hülle‘) oder eingedeutscht Kortex bezeichnet: Rinde einer Pflanze in der Botanik Rindenteile einer Heilpflanze, siehe Heilpflanze #Bezeichnungen für die jeweils wirksamen Teile der Pflanze Rindenschicht der Fruchtkörper bei… …   Deutsch Wikipedia

  • Cortex — Cor tex (k[^o]r t[e^]ks), n.; pl. {Cortices} ( t? s?z). [L., bark. Cf. {Cork}.] 1. Bark, as of a tree; hence, an outer covering. [1913 Webster] 2. (Med.) Bark; rind; specifically, cinchona bark. [1913 Webster] 3. (Anat.) The outer or superficial… …   The Collaborative International Dictionary of English

  • córtex — m. anat. Corteza. Medical Dictionary. 2011 …   Diccionario médico

  • cortex — 1650s, outer shell, husk, from L. cortex bark of a tree (see CORIUM (Cf. corium)). Specifically of the brain, first recorded 1741 …   Etymology dictionary

  • cortex — meaning ‘the outer part of a bodily organ’ (as in cerebral cortex, referring to the brain), has the plural form cortices …   Modern English usage

  • cortex — ► NOUN (pl. cortices) Anatomy ▪ the outer layer of an organ or structure, especially the outer, folded layer of the brain (cerebral cortex). DERIVATIVES cortical adjective. ORIGIN Latin, bark …   English terms dictionary

  • cortex — cortex. См. кортекс. (Источник: «Англо русский толковый словарь генетических терминов». Арефьев В.А., Лисовенко Л.А., Москва: Изд во ВНИРО, 1995 г.) …   Молекулярная биология и генетика. Толковый словарь.

  • Cortex — (lat.), 1) Rinde, bes. zu pharmaceutischem Gebrauch, z.B. C. angosturae, s. Angosturarinde etc.; 2) (Anat.), so v.w. Rindensubstanz, z.B. des Gehirns, auch Corticalsubstanz …   Pierer's Universal-Lexikon


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