Cortex (Latin for bark) has different meanings, depending on the context.

Contents

1 Neuroanatomy 2 Botany 3 Anatomy and Zoology 4 Archaeology

Neuroanatomy

In neuroanatomy the cortex is the outermost layer of the brain. It is rich in neurons and is the site of most sophisticated neural processing (See also: cerebral cortex). Or, more generally, the outermost portion of certain biological structures (See below). The human cortex is 1-4 mm thick, with an area (if it were spread flat) of about 0.22 m². It comprises perhaps 10⁹ neurons, which appear to be organized in clusters called minicolumns, each having 80-100 neurons in a diameter of 30-50 µm.

Botany

In botany the cortex is the outer portion of the stem or root of a plant, bounded on the outside by the epidermis and on the inside by the pericycle. It is composed mostly of undifferentiated cells , usually large thin-walled parenchyma cells. The outer cortical cells often acquire irregularly thickened cell walls, cand are called collenchyma cells. Some of the outer cortical cells may contain chloroplasts. Its main function is the storage of starch; often, it also provides aeration of cells to allow respiration.

Anatomy and Zoology

In anatomy and zoology the cortex 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.

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 (100% cortex), secondary (100%>x>0%), and tertiary (0%). The amount of cortex present on artefacts in an archaeological assemblage may indicate the extent of lithic reduction that has occurred.