anatomy Anatomy () is the branch of morphology concerned with the study of the internal structure of organisms and their parts. Anatomy is a branch of natural science that deals with the structural organization of living things. It is an old scien ...

and

zoology Zoology ( , ) is the scientific study of animals. Its studies include the anatomy, structure, embryology, Biological classification, classification, Ethology, habits, and distribution of all animals, both living and extinction, extinct, and ...

, the cortex (: cortices) is the outermost, otherwise known as superficial, layer of an organ. Organs with well-defined cortical layers include

kidney In humans, the kidneys are two reddish-brown bean-shaped blood-filtering organ (anatomy), organs that are a multilobar, multipapillary form of mammalian kidneys, usually without signs of external lobulation. They are located on the left and rig ...

adrenal gland The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer adrenal corte ...

ovaries The ovary () is a gonad in the female reproductive system that produces ova; when released, an ovum travels through the fallopian tube/oviduct into the uterus. There is an ovary on the left and the right side of the body. The ovaries are endocr ...

, the

thymus The thymus (: thymuses or thymi) is a specialized primary lymphoid organ of the immune system. Within the thymus, T cells mature. T cells are critical to the adaptive immune system, where the body adapts to specific foreign invaders. The thymus ...

, and portions of the

brain The brain is an organ (biology), organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It consists of nervous tissue and is typically located in the head (cephalization), usually near organs for ...

, including the

cerebral cortex The cerebral cortex, also known as the cerebral mantle, is the outer layer of neural tissue of the cerebrum of the brain in humans and other mammals. It is the largest site of Neuron, neural integration in the central nervous system, and plays ...

, the best-known of all cortices.

Etymology

The word is of

Latin Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

origin and means bark, rind, shell or husk.

Notable examples

* The renal cortex, between the renal capsule and the

renal medulla The renal medulla (Latin: ''medulla renis'' 'marrow of the kidney') is the innermost part of the kidney. The renal medulla is split up into a number of sections, known as the renal pyramids. Blood enters into the kidney via the renal artery, which ...

; assists in ultrafiltration * The adrenal cortex, situated along the perimeter of the

; mediates the stress response through the production of various hormones * The thymic cortex, mainly composed of lymphocytes; functions as a site for somatic recombination of T cell receptors, and positive selection * The

, the outer layer of the cerebrum, plays a key role in memory, attention, perceptual awareness, thought, language, and consciousness. *

Cortical bone A bone is a rigid organ that constitutes part of the skeleton in most vertebrate animals. Bones protect the various other organs of the body, produce red and white blood cells, store minerals, provide structure and support for the body, an ...

is the hard outer layer of bone; distinct from the spongy, inner cancellous bone tissue * Ovarian cortex is the outer layer of the ovary and contains the follicles. * The lymph node cortex is the outer layer of the lymph node.

Cerebral cortex

The cerebral cortex is typically described as comprising three parts: the sensory, motor, and association areas. These sensory areas receive and process information from the senses. The senses of vision, audition, and touch are served by the primary

visual cortex The visual cortex of the brain is the area of the cerebral cortex that processes visual information. It is located in the occipital lobe. Sensory input originating from the eyes travels through the lateral geniculate nucleus in the thalam ...

, the primary auditory cortex, and primary somatosensory cortex. The cerebellar cortex is the thin gray surface layer of the

cerebellum The cerebellum (: cerebella or cerebellums; Latin for 'little brain') is a major feature of the hindbrain of all vertebrates. Although usually smaller than the cerebrum, in some animals such as the mormyrid fishes it may be as large as it or eve ...

, consisting of an outer molecular layer or stratum moleculare, a single layer of Purkinje cells (the ganglionic layer), and an inner granular layer or

stratum granulosum The stratum granulosum (or granular layer) is a thin layer of cells in the epidermis lying above the stratum spinosum and below the stratum corneum ( stratum lucidum on the soles and palms).James, William; Berger, Timothy; Elston, Dirk (2005) ''A ...

. The cortex is the outer surface of the

cerebrum The cerebrum (: cerebra), telencephalon or endbrain is the largest part of the brain, containing the cerebral cortex (of the two cerebral hemispheres) as well as several subcortical structures, including the hippocampus, basal ganglia, and olfac ...

and is composed of gray matter. The motor areas are located in both hemispheres of the cerebral cortex. Two areas of the cortex are commonly referred to as motor: the primary motor cortex, which executes voluntary movements; and the supplementary motor areas and

premotor cortex The premotor cortex is an area of the motor cortex lying within the frontal lobe of the brain just anterior to the primary motor cortex. It occupies part of Brodmann's area 6. It has been studied mainly in primates, including monkeys and human ...

, which ''select'' voluntary movements. In addition, motor functions have been attributed to the posterior parietal cortex, which guides voluntary movements; and the

dorsolateral prefrontal cortex The dorsolateral prefrontal cortex (DLPFC or DL-PFC) is an area in the prefrontal cortex of the primate brain. It is one of the most recently derived parts of the human brain. It undergoes a prolonged period of maturation which lasts into adulthoo ...

, which decides which voluntary movements to make according to higher-order instructions, rules, and self-generated thoughts. The association areas of the cerebral cortex organize information received from the sensory and motor areas. The association areas of the human brain are highly developed, and are thought to play an integral role in complex functions. The association areas can be divided into 3 categories: the parasensory association cortex, the frontal association cortex, and the paralimbic association cortex. The parasensory association cortex receives signals from the primary sensory areas. The paralimbic association cortex connects with the organs of the limbic system. The frontal association cortex can be split into the premotor cortex and the prefrontal cortex. The premotor cortex is sent signals from the primary motor cortex, and the prefrontal cortex is sent signals from the premotor cortex.

References

Anatomy {{Anatomy-stub