cortexes

Cortex (plural cortexes or cortices) denotes an outer layer or rind that surrounds a structure. The term is used across disciplines such as neuroscience, anatomy, and botany. In formal scientific writing, cortices is often preferred for many terms (such as cerebral cortices), though cortexes appears in general usage.

In neuroanatomy, the cerebral cortex is the outer layer of the cerebrum, made of gray matter with a characteristic six-layer organization. It contains specialized regions for perception, movement, language, memory, and higher cognition. Cortical development occurs during fetal life through neuronal migration, and the mature cortex remains plastic, supporting learning and adaptation.

In endocrinology and nephrology, the adrenal cortex is the outer portion of the adrenal gland, producing corticosteroids such as cortisol and aldosterone. The renal cortex is the outer part of the kidney, containing glomeruli and parts of the nephron. These cortices regulate metabolism, fluid balance, and overall homeostasis.

In botany, the cortex is the layer between the epidermis and vascular tissue in stems and roots. It is mainly parenchyma tissue that stores starch and may contribute to transport and nutrient storage. In roots, the cortex lies between the epidermis and endodermis and can include air spaces.

Other usages include the cortical bone, the dense outer layer of a bone, and various outer coverings in invertebrates. Across contexts, the cortex generally refers to an outer functional or protective layer.