- In anatomy, the cortex is the superficial layer
of an organ. Included are such organs
as the kidney, adrenal
gland, ovary, thymus
gland, and brain. Among these examples
the cerebral cortex of the brain
is the most familiar. The term designates no common characteristic of
origin or structure, but only the existence of a distinctive layer at
the surface of the organ involved.
- In botany, the cortex is the outer portion of
a stem or root,
bounded externally by the epidermis,
and internally by the cells of the pericycle. The cortex is composed
mostly of cells which are very little differentiated. Usually these
are rather large, thin walled parenchyma cells. The outer cortical cells often acquire irregularly thickened
cell walls. These are the collenchyma cells. Some of the outer cortex cells may contains chloroplasts and carry on photosynthesis.