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Human brain

In animals, the brain is the control center of the central nervous system, responsible for behavior. In mammals, the brain is located in the head, protected by the skull and close to the primary sensory apparatus of vision, hearing, equilibrioception (balance), sense of taste, and olfaction (smell). Image File history File links Question_book-3. ... The term brain refers to more than one thing: The brain is an organ part of many vertebrates nervous systems. ... Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... A human brain. ... A diagram showing the CNS: 1. ... This article does not cite any references or sources. ... For other uses of Skull, see Skull (disambiguation). ... In psychology, visual perception is the ability to interpret information from visible light reaching the eyes. ... Hearing (or audition) is one of the traditional five senses, and refers to the ability to detect sound. ... Equilibrioception or sense of balance is one of the physiological senses. ... Taste (or, more formally, gustation) is a form of direct chemoreception and is one of the traditional five senses. ... Olfaction (also known as olfactics) refers to the sense of smell. ...

While all vertebrates have a brain, most invertebrates have either a centralized brain or collections of individual ganglia. Some animals such as cnidarians and echinoderms do not have a centralized brain, and instead have a decentralized nervous system, while animals such as sponges lack both a brain and nervous system entirely. This article does not cite any references or sources. ... Invertebrate is an English word that describes any animal without a spinal column. ... This is a dorsal root ganglion (DRG) from a chicken embryo (around stage of day 7) after incubation overnight in NGF growth medium stained with anti-neurofilament antibody. ... Classes Anthozoa - Corals and sea anemones Cubozoa - Sea wasps or box jellyfish Hydrozoa - Hydroids, hydra-like animals Scyphozoa - Jellyfish Cnidaria is a phylum containing some 10,000 species of relatively simple animals found exclusively in aquatic environments (most species are marine). ... Subphyla & Classes Homalozoa Gill & Caster, 1960 Homostelea Homoiostelea Stylophora † Ctenocystoidea Robison & Sprinkle, 1969 Crinozoa Crinoidea Paracrinoidea † Regnéll, 1945 Cystoidea †von Buch, 1846 Asterozoa Ophiuroidea Asteroidea Echinozoa Echinoidea Holothuroidea Ophiocistioidea Helicoplacoidea † Arkarua † Homalozoa † Pelmatozoa † Edrioasteroidea † Blastozoa † Blastoidea † Eocrinoidea †Jaekel, 1899 † = extinct Echinoderms (Phylum Echinodermata, from the Greek for spiny skin... This article is about the aquatic animal. ...

Brains can be extremely complex. For example, the human brain contains roughly 100 billion neurons, each linked to as many as 10,000 other neurons. A human brain. ... This article is about cells in the nervous system. ...

History

Main article: History of the brain

Early views on the function of the brain regarded it as little more than cranial stuffing. In Ancient Egypt, from the late Middle Kingdom onwards, in preparation for mummification, the brain was regularly removed, for it was the heart that was assumed to be the seat of intelligence. According to Herodotus, during the first step of mummification, "The most perfect practice is to extract as much of the brain as possible with an iron hook, and what the hook cannot reach is mixed with drugs." Over the next five-thousand years, this view came to be reversed; the brain is now known to be seat of intelligence, although idiomatic variations of the former remain, as in memorizing something "by heart".^[1] For other uses, see evolution. ... The pyramids are the most recognizable symbols of the civilization of ancient Egypt. ... The Middle Kingdom is: a old name for China a period in the History of Ancient Egypt, the Middle Kingdom of Egypt This is a disambiguation page — a navigational aid which lists pages that might otherwise share the same title. ... Look up mummification in Wiktionary, the free dictionary. ... The heart and lungs, from an older edition of Grays Anatomy. ... Herodotus of Halicarnassus (Greek: Hēródotos Halikarnāsseús) was a Greek historian who lived in the 5th century BC (c. ... An idiom is an expression (i. ...

The first thoughts on the field of psychology came from ancient philosophers, such as Aristotle. As thinkers became more in tune with biomedical research over time, as was the case with medieval psychologists such as Alhazen and Avicenna for example, the concepts of experimental psychology and clinical psychology began emerging. From that point, different branches of psychology emerged with different individuals creating new ideas, with modern psychologists such as Freud and Jung contributing to the field. {redirect|Psychological science|the journal|Psychological Science (journal)}} Not to be confused with Phycology. ... This page lists some links to ancient philosophy, although for Western thinkers prior to Socrates, see Pre-Socratic philosophy. ... For other uses, see Aristotle (disambiguation). ... Biomedical research (or experimental medicine), in general simply known as medical research, is the basic research or applied research conducted to aid the body of knowledge in the field of medicine. ... Early Muslim sociology responded to the challenges of social organization of diverse peoples all under common religious organization in the Islamic caliphate, the Abbasid and later Mamluk period in Egypt. ... (Arabic: أبو علي الحسن بن الحسن بن الهيثم, Latinized: Alhacen or (deprecated) Alhazen) (965 – 1039), was an Arab[1] Muslim polymath[2][3] who made significant contributions to the principles of optics, as well as to anatomy, astronomy, engineering, mathematics, medicine, ophthalmology, philosophy, physics, psychology, visual perception, and to science in general with his introduction of the... (Persian: ابن سينا) (c. ... Experimental psychology approaches psychology as one of the natural sciences, and therefore assumes that it is susceptible to the experimental method. ... The Greek letter Psi is often used as a symbol of psychology. ... A psychologist is an expert in psychology, the systematic investigation of the human body, including behavior, cognition, and affect. ... Sigmund Freud (IPA: ), born Sigismund Schlomo Freud (May 6, 1856 – September 23, 1939), was an Austrian neurologist and psychiatrist who founded the psychoanalytic school of psychology. ... Jung redirects here. ...

Mind and brain

Mind and Brain Portal

The distinction between the mind and the brain is fundamental in philosophy of mind. The mind-body problem is one of the central problems in the history of philosophy. The brain is the physical and biological matter contained within the skull, responsible for electrochemical neuronal processes. The mind, in contrast, consists in mental attributes, such as beliefs, desires, perceptions, and so on. There are scientifically demonstrable correlations between mental events and neuronal events; the philosophical question is whether these phenomena are identical or are related in some other way. Image File history File links Portal. ... For other uses, see Mind (disambiguation). ... A phrenological mapping of the brain. ... To meet Wikipedias quality standards, this article may require cleanup. ... This article is about matter in physics and chemistry. ... For other uses of Skull, see Skull (disambiguation). ...

The philosophical positions on the mind-body problem fall into two main categories. The first category is dualism, according to which the mind exists independently of the brain. Dualist theories are further divided into substance dualism and property dualism. Descartes is perhaps the most prominent substance dualist, while property dualism is more popular among contemporary dualists like David Chalmers. The second category is materialism, according to which mental phenomena are identical to neuronal phenomena. A third category of view, idealism, claims that only mental substances and phenomena exist. This view, most prominently held by 18th century English philosopher George Berkeley, has few contemporary adherents. René Descartes illustration of dualism. ... In philosophy, materialism is that form of physicalism which holds that the only thing that can truly be said to exist is matter; that fundamentally, all things are composed of material and all phenomena are the result of material interactions; that matter is the only substance. ...

Both dualism and materialism face serious philosophical challenges. Dualism requires that we admit non-physical substances or properties into our ontology, a move that places dualism in apparent conflict with the scientific world view. Materialism, on the other hand, must provide an explanation of how two seemingly different kinds of phenomena – the mental and the physical – could be identical. This challenge can be seen by noting that mental phenomena have certain characteristics – particularly intentionality and phenomenal character – that physical phenomena do not, and seemingly could not, have.

Comparative anatomy

A mouse brain.

Three groups of animals have notably complex brains: the arthropods (insects, crustaceans, arachnids, and others), the cephalopods (octopuses, squids, and similar mollusks), and the craniates (vertebrates and hagfish).^[2] The brain of arthropods and cephalopods arises from twin parallel nerve cords that extend through the body of the animal. Arthropods have a central brain with three divisions and large optical lobes behind each eye for visual processing.^[2] A mouse brain. ... A mouse brain. ... Subphyla and Classes Subphylum Trilobitomorpha Trilobita - trilobites (extinct) Subphylum Chelicerata Arachnida - spiders,scorpions, etc. ... Orders Subclass Apterygota Archaeognatha (bristletails) Thysanura (silverfish) Subclass Pterygota Infraclass Paleoptera (Probably paraphyletic) Ephemeroptera (mayflies) Odonata (dragonflies and damselflies) Infraclass Neoptera Superorder Exopterygota Grylloblattodea (ice-crawlers) Mantophasmatodea (gladiators) Plecoptera (stoneflies) Embioptera (webspinners) Zoraptera (angel insects) Dermaptera (earwigs) Orthoptera (grasshoppers, etc) Phasmatodea (stick insects) Blattodea (cockroaches) Isoptera (termites) Mantodea (mantids) Psocoptera... For the Dutch band, see Crustacean (band). ... For other uses, see Arachnid (disambiguation). ... Orders Subclass Nautiloidea †Plectronocerida †Ellesmerocerida †Actinocerida †Pseudorthocerida †Endocerida †Tarphycerida †Oncocerida †Discosorida Nautilida †Orthocerida †Ascocerida †Bactritida Subclass †Ammonoidea †Goniatitida †Ceratitida †Ammonitida Subclass Coleoidea †Belemnoidea †Aulacocerida †Belemnitida †Hematitida †Phragmoteuthida Neocoleoidea (most living cephalopods) ?†Boletzkyida Sepiida Sepiolida Spirulida Teuthida Octopoda Vampyromorphida The cephalopods (Greek plural (kephalópoda); head-foot) are the mollusc class... For other uses, see Octopus (disambiguation). ... For other uses, see Squid (disambiguation). ... Classes Caudofoveata Aplacophora Polyplacophora Monoplacophora Bivalvia Scaphopoda Gastropoda Cephalopoda † Rostroconchia The mollusks or molluscs are the large and diverse phylum Mollusca, which includes a variety of familiar creatures well-known for their decorative shells or as seafood. ... Classes Hyperotreti Vertebrata Craniata is a type of chordate animal group that contains vertebrates (vertebrata) and hagfish (Hyperotreti). ... This article does not cite any references or sources. ... For the punk rock band, see Hagfish (band). ... For other uses, see Eye (disambiguation). ...

The brain of craniates develops from the anterior section of a single dorsal nerve cord, which later becomes the spinal cord.^[3] In craniates, the brain is protected by the bones of the skull. In sciences dealing with the anatomy of animals, precise anatomical terms of location are necessary for a variety of reasons. ... In the developing vertebrate nervous system, the neural tube is the precursor of the central nervous system, which comprises the brain and spinal cord. ... The Spinal cord nested in the vertebral column. ... This article is about the skeletal organs. ... For other uses of Skull, see Skull (disambiguation). ...

Mammals have a six-layered neocortex (or homotypic cortex, neopallium), in addition to having some parts of the brain that are allocortex.^[3] In mammals, increasing convolutions of the brain are characteristic of animals with more advanced brains. These convolutions provide a larger surface area for a greater number of neurons while keeping the volume of the brain compact enough to fit inside the skull. The folding allows more grey matter to fit into a smaller volume, similar to a really long slinky being able to fit into a tiny box when completely pushed together. The folds are called sulci, while the spaces between the folds are called gyri. Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria For the folk-rock band see The Mammals. ... The neocortex (Latin for new bark or new rind) is a part of the brain of mammals. ... Grays Fig. ... Grays FIG. 726– Lateral surface of left cerebral hemisphere, viewed from the side. ...

In birds, the part of the brain that functionally corresponds to the neocortex is called nidopallium and derives from a different part of the brain. Some birds (like corvids and parrots), are thought by some to have high intelligence, but even in these, the brain region that forms the mammalian neocortex is in fact almost entirely absent. For other uses, see Bird (disambiguation). ... The nidopallium, meaning nested pallium, is the region of the avian brain that is used mostly for some types of executive functions but also other higher cognitive tasks. ... Genera Platylophus Gymnorhinus Cyanocitta Aphelocoma Cyanocorax Garrulus Cissa Perisoreus Urocissa Cyanopica Dendrocitta Crypsirina Pica Zavattariornis Podoces Nucifraga Pyrrhocorax Ptilostomus Corvus The crow family (Corvidae) has members that are above average in size for the bird order Passeriformes; in fact, it includes several that are among the largest. ... Systematics (but see below) Family Cacatuidae (cockatoos) Subfamily Microglossinae (Palm Cockatoo) Subfamily Calyptorhynchinae (dark cockatoos) Subfamily Cacatuinae (white cockatoos) Family Psittacidae (true parrots) Subfamily Loriinae (lories and lorikeets) Subfamily Psittacinae (typical parrots and allies) Tribe Arini (American psittacines) Tribe Cyclopsitticini (fig parrots) Tribe Micropsittini (pygmy parrots) Tribe Nestorini (kakas and...

Although the general histology of the brain is similar from person to person, the structural anatomy can differ. Apart from the gross embryological divisions of the brain, the location of specific gyri and sulci, primary sensory regions, and other structures differs between species. A thin section of lung tissue stained with hematoxylin and eosin. ... This article or section is in need of attention from an expert on the subject. ...

Insects

In insects, the brain has four parts, the optical lobes, the protocerebrum, the deutocerebrum, and the tritocerebrum. The optical lobes are behind each eye and process visual stimuli.^[2] The protocerebrum contains the mushroom bodies, which respond to smell, and the central body complex. In some species such as bees, the mushroom body receives input from the visual pathway as well. The deutocerebrum includes the antennal lobes, which are similar to the mammalian olfactory bulb, and the mechanosensory neuropils which receive information from touch receptors on the head and antennae. The antennal lobes of flies and moths are quite complex. The mushroom bodies or corpora pedunculata are a pair of structures in the brain of insects and other arthropods. ... Olfaction (also known as olfactics) refers to the sense of smell. ... For other uses, see Species (disambiguation). ... For other uses, see Western honey bee and Bee (disambiguation). ... Antennal Lobe is the deutocerebral neuropil of the insect which receive the input from the sensory neurons on the antenna. ... The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors. ... Neuropil is the feltwork of unmyelinated neuronal processes (axonal and dendritic) within the gray matter of the central nervous system Traditionally, when pathologists looked at brain tissue they concentrated on neurons (the active functioning cells of the brain), glial cells and axons (especially in white matter, which is mostly composed... Touch redirects here. ... Insects display a wide variety of antennal shapes. ... For other uses, see Fly (disambiguation) and Flies (disambiguation). ... For other uses, see Moths. ...

Cephalopods

In cephalopods, the brain has two regions: the supraesophageal mass and the subesophageal mass,^[2] separated by the esophagus. The supra- and subesophageal masses are connected to each other on either side of the esophagus by the basal lobes and the dorsal magnocellular lobes.^[2] The large optic lobes are sometimes not considered to be part of the brain, as they are anatomically separate and are joined to the brain by the optic stalks. However, the optic lobes perform much visual processing, and so functionally are part of the brain. The esophagus or oesophagus (see American and British English spelling differences), sometimes known as the gullet, is an organ in vertebrates which consists of a muscular tube through which food passes from the pharynx to the stomach. ...

Mammals and other vertebrates

The telencephalon (cerebrum) is the largest region of the mammalian brain. This is the structure that is most easily visible in brain specimens, and is what most people associate with the "brain". In humans and several other animals, the fissures (sulci) and convolutions (gyri) give the brain a wrinkled appearance. In non-mammalian vertebrates with no cerebrum, the metencephalon is the highest center in the brain. Because humans walk upright, there is a flexure, or bend, in the brain between the brain stem and the cerebrum. Other vertebrates do not have this flexure. Generally, comparing the locations of certain brain structures between humans and other vertebrates often reveals a number of differences. The telencephalon (te-len-seff-a-lon) is the technical name for a large region within the brain which is attributed many functions, which some groups would class as unique features which make humans stand out from other species. ... The metencephalon is a developmental categorization of portions of the central nervous system. ... The brain stem is the lower part of the brain, adjoining and structurally continuous with the spinal cord. ...

Behind (or in humans, below) the cerebrum is the cerebellum. The cerebellum is known to be involved in the control of movement,^[3] and is connected by thick white matter fibers (cerebellar peduncles) to the pons.^[4] The cerebrum has two cerebral hemispheres. The cerebellum also has hemispheres. The telencephalic hemispheres are connected by the corpus callosum, another large white matter tract. An outgrowth of the telencephalon called the olfactory bulb is a major structure in many animals, but in humans and other primates it is relatively small. For other uses, see Pons (disambiguation). ... Human brain viewed from above, showing cerebral hemispheres. ... The cerebellum (Latin: little brain) is a region of the brain that plays an important role in the integration of sensory perception and motor control. ... The corpus callosum is a structure of the mammalian brain in the longitudal fissure that connects the left and right cerebral hemispheres. ... The olfactory bulb is a structure of the vertebrate forebrain involved in olfaction, the perception of odors. ...

Vertebrate nervous systems are distinguished by bilaterally symmetrical encephalization. Encephalization refers to the tendency for more complex organisms to gain larger brains through evolutionary time. Larger vertebrates develop a complex, layered and interconnected neuronal circuitry. In modern species most closely related to the first vertebrates, brains are covered with gray matter that has a three-layer structure (allocortex). Their brains also contain deep brain nuclei and fiber tracts forming the white matter. Most regions of the human cerebral cortex have six layers of neurons (neocortex).^[4] The elaborate patterns on the wings of butterflies are one example of bilateral symmetry. ... Encephalization is defined as the amount of brain mass exceeding that related to an animals total body mass. ...

Vertebrate brain regions

(See related article at List of regions in the human brain) // medulla oblongata medullary pyramids pons paramedian pontine reticular formation fourth ventricle cerebellum cerebellar vermis cerebellar hemispheres anterior lobe posterior lobe flocculonodular lobe cerebellar nuclei fastigial nucleus globose nucleus emboliform nucleus dentate nucleus tectum inferior colliculi superior colliculi mesencephalic duct (cerebral aqueduct, Aqueduct of Sylvius) cerebral peduncle midbrain tegmentum ventral tegmental...

Diagram depicting the main subdivisions of the embryonic vertebrate brain. These regions will later differentiate into forebrain, midbrain and hindbrain structures.

According to the hierarchy based on embryonic and evolutionary development, chordate brains are composed of the three regions that later develop into five total divisions: Image File history File links This is a lossless scalable vector image. ... Image File history File links This is a lossless scalable vector image. ... Embryogenesis is the process by which the embryo is formed and develops. ... Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ...

• Rhombencephalon (hindbrain)
  • Myelencephalon
  • Metencephalon
• Mesencephalon (midbrain)
• Prosencephalon (forebrain)
  • Diencephalon
  • Telencephalon

The brain can also be classified according to function, including divisions such as: The rhombencephalon (or hindbrain) is a developmental categorization of portions of the central nervous system in vertebrates. ... The myelencephalon is a developmental categorization of a portion of the central nervous system. ... The metencephalon is a developmental categorization of portions of the central nervous system. ... In biological anatomy, the mesencephalon (or midbrain) is the middle of three vesicles that arise from the neural tube that forms the brain of developing animals. ... In the anatomy of vertebrates, the prosencephalon is a part of encephalon, or brain. ... The diencephalon is the region of the brain that includes the epithalamus, thalamus, and hypothalamus. ... The telencephalon (te-len-seff-a-lon) is the technical name for a large region within the brain which is attributed many functions, which some groups would class as unique features which make humans stand out from other species. ...

• Limbic system
• Sensory systems
  • Visual system
  • Olfactory system
  • Gustatory system
  • Auditory system
  • Somatosensory system
• Motor system
• Associative areas

In recent years it was realized that certain birds have developed high intelligence entirely convergently from mammals such as humans. Hence, the functional areas of the avian brain have been redefined by the Avian Brain Nomenclature Consortium. See also Bird intelligence. The limbic system is a historically defined set of brain structures that support a variety of functions including emotion and memory. ... The human eye is the first element of a sensory system: in this case, vision, for the visual system. ... The visual system is the part of the nervous system which allows organisms to see. ... The olfactory system is the sensory system used for olfaction. ... The gustatory system is the sensory system that uses taste buds (or lingual papillae) on the upper surface of the tongue to provide information about the taste of food being eaten. ... The auditory system is the sensory system for the sense of hearing. ... Touch redirects here. ... For other uses of Muscle, see Muscle (disambiguation). ... For other uses, see Cortex. ... For other uses, see Bird (disambiguation). ... In evolutionary biology, convergent evolution is the process whereby organisms not closely related, independently evolve similar traits as a result of having to adapt to similar environments or ecological niches. ... Orders Subclass Monotremata Monotremata Subclass Marsupialia Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Subclass Placentalia Xenarthra Dermoptera Desmostylia Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia The mammals are the class of vertebrate animals primarily characterized by the presence of mammary... The Avian Brain Nomenclature Consortium is a group of neuroscientists working on standardizing and updating the scientific language used to describe parts of bird brains. ... Bird intelligence deals with the definition of intelligence and its measurement as it applies to birds. ...

Humans

Human brain with color coded lobes

Main article: human brain

The structure of the human brain differs from that of other animals in several important ways. These differences allow for many abilities over and above those of other animals, such as advanced cognitive skills. Human encephalization is especially pronounced in the neocortex, the most complex part of the cerebral cortex. The proportion of the human brain that is devoted to the neocortex—especially to the prefrontal cortex—is larger than in all other mammals (indeed larger than in all animals, although only in mammals has the neocortex evolved to fulfill this kind of function). Image File history File links Brain_animated_color_nevit. ... Image File history File links Brain_animated_color_nevit. ... A human brain. ... The neocortex (Latin for new bark or new rind) is a part of the brain of mammals. ... For other uses, see Cortex. ... “Prefrontal” redirects here. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria For the folk-rock band see The Mammals. ...

Humans have unique neural capacities, but much of their brain structure is similar to that of other mammals. Basic systems that alert the nervous system to stimulus, that sense events in the environment, and monitor the condition of the body are similar to those of even non-mammalian vertebrates. The neural circuitry underlying human consciousness includes both the advanced neocortex and prototypical structures of the brainstem. The human brain also has a massive number of synaptic connections allowing for a great deal of parallel processing. The brain stem is the stalk of the brain below the cerebral hemispheres. ... Parallel processing is the ability of the brain to simultaneously process incoming stimuli. ...

Neurobiology

The brain is composed of two broad classes of cells, neurons and glia, both of which contain several different cell types which perform different functions. Interconnected neurons form neural networks (or neural ensembles). These networks are similar to man-made electrical circuits in that they contain circuit elements (neurons) connected by biological wires (nerve fibers). These do not form simple one-to-one electrical circuits like many man-made circuits, however. Typically neurons connect to at least a thousand other neurons.^[5] These highly specialized circuits make up systems which are the basis of perception, different types of action, and higher cognitive function. This article is about cells in the nervous system. ... Neuroglia cells of the brain shown by Golgis method. ... // Traditionally, the term neural network had been used to refer to a network or circuitry of biological neurons. ... A population of brain cells involved in a particular neural computation. ... An electrical network or electrical circuit is an interconnection of analog electrical elements such as resistors, inductors, capacitors, diodes, switches and transistors. ... In psychology and the cognitive sciences, perception is the process of acquiring, interpreting, selecting, and organizing sensory information. ...

Structure

Structure of a typical neuron

Neuron
Dendrite Soma Axon Nucleus Node of Ranvier Axon Terminal Schwann cell Myelin sheath

Neurons are the cells that convey information to other cells; these constitute the essential class of brain cells. This article is about cells in the nervous system. ... Image File history File links Neuron-no_labels. ... Dendrites (from Greek dendron, “tree”) are the branched projections of a neuron that act to conduct the electrical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. ... The soma, or perikaryon, is the bulbous end of a neuron, containing the cell nucleus. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... HeLa cells stained for DNA with the Blue Hoechst dye. ... Nodes of Ranvier are regularly spaced gaps in the myelin sheath around an axon or nerve fiber. ... Nodes of Ranvier are regularly spaced gaps in the myelin sheath around an axon or nerve fiber. ... Illustration of the major elements in a prototypical synapse. ... Named after the German physiologist Theodor Schwann, Schwann cells are a variety of neuroglia that mainly provide myelin insulation to axons in the peripheral nervous system of jawed vertebrates. ... In neuroscience, myelin is an electrically insulating fatty layer that surrounds the axons of many neurons, especially those in the peripheral nervous system. ...

In addition to neurons, the brain contains glial cells in a roughly 10:1 proportion to neurons. Glial cells ("glia" is Greek for “glue”) form a support system for neurons. They create the insulating myelin, provide structure to the neuronal network, manage waste, and clean up neurotransmitters. Most types of glia in the brain are present in the entire nervous system. Exceptions include the oligodendrocytes which myelinate neural axons (a role performed by Schwann cells in the peripheral nervous system). The myelin in the oligodendrocytes insulates the axons of some neurons. White matter in the brain is myelinated neurons, while grey matter contains mostly cell soma, dendrites, and unmyelinated portions of axons and glia. The space between neurons is filled with dendrites as well as unmyelinated segments of axons; this area is referred to as the neuropil. Neuroglia of the brain shown by Golgis method. ... The nervous system is a highly specialized network whose principal components are nerves called neurons. ... Oligodendrocytes (from Greek literally meaning few tree cells), or oligodendroglia (Greek, few tree glue),[1] are a variety of neuroglia. ... An axon or nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses away from the neurons cell body or soma. ... Named after the German physiologist Theodor Schwann, Schwann cells are a variety of neuroglia that mainly provide myelin insulation to axons in the peripheral nervous system of jawed vertebrates. ... White matter is one of the two main solid components of the central nervous system. ... Gray matter redirects here. ... The soma, or perikaryon, is the bulbous end of a neuron, containing the cell nucleus. ... Dendrites (from Greek dendron, “tree”) are the branched projections of a neuron that act to conduct the electrical stimulation received from other neural cells to the cell body, or soma, of the neuron from which the dendrites project. ... Neuropil is the feltwork of unmyelinated neuronal processes (axonal and dendritic) within the gray matter of the central nervous system Traditionally, when pathologists looked at brain tissue they concentrated on neurons (the active functioning cells of the brain), glial cells and axons (especially in white matter, which is mostly composed...

In mammals, the brain is surrounded by connective tissues called the meninges, a system of membranes that separate the skull from the brain. This three-layered covering is composed of (from the outside in) the dura mater, arachnoid mater, and pia mater. The arachnoid and pia are physically connected and thus often considered as a single layer, the pia-arachnoid. Below the arachnoid is the subarachnoid space which contains cerebrospinal fluid, a substance that protects the nervous system. Blood vessels enter the central nervous system through the perivascular space above the pia mater. The cells in the blood vessel walls are joined tightly, forming the blood-brain barrier which protects the brain from toxins that might enter through the blood. Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue. ... The meninges (singular meninx) are the system of membranes that envelop the central nervous system. ... It has been suggested that Net flux be merged into this article or section. ... The dura mater (from the Latin hard mother), or pachymeninx, is the tough and inflexible outermost of the three layers of the meninges surrounding the brain. ... The Arachnoid mater is one of the three layers of the meninges, interposed between the dura mater and the pia mater and separated from the pia mater by the subarachnoid space. ... [www. ... Cerebrospinal fluid (CSF), Liquor cerebrospinalis, is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). ... f you all The blood vessels are part of the circulatory system and function to transport blood throughout the body. ... The blood-brain barrier (BBB) is a membranic structure that acts primarily to protect the brain from chemicals in the blood, while still allowing essential metabolic function. ... For other uses, see Toxin (disambiguation). ...

The brain is bathed in cerebrospinal fluid (CSF), which circulates between layers of the meninges and through cavities in the brain called ventricles. It is important both chemically for metabolism and mechanically for shock-prevention. For example, the human brain weighs about 1-1.5 kg or about 2-3 lb. The mass and density of the brain are such that it will begin to collapse under its own weight if unsupported by the CSF. The CSF allows the brain to float, easing the physical stress caused by the brain’s mass. Cerebrospinal fluid (CSF), Liquor cerebrospinalis, is a clear bodily fluid that occupies the subarachnoid space in the brain (the space between the skull and the cerebral cortex—more specifically, between the arachnoid and pia layers of the meninges). ... The ventricular system is a set of structures in the brain continuous with the central canal of the spinal cord. ... Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ... The international prototype, made of platinum-iridium, which is kept at the BIPM under conditions specified by the 1st CGPM in 1889. ... Look up pound in Wiktionary, the free dictionary. ... For other uses, see Mass (disambiguation). ... For other uses, see Density (disambiguation). ... Stress is a measure of force per unit area within a body. ...

Function

Vertebrate brains receive signals through nerves arriving from the sensors of the organism. These signals are then processed throughout the central nervous system; reactions are formulated based upon reflex and learned experiences. A similarly extensive nerve network delivers signals from a brain to control important muscles throughout the body. Anatomically, the majority of afferent and efferent nerves (with the exception of the cranial nerves) are connected to the spinal cord, which then transfers the signals to and from the brain. Cranial nerves Cranial nerves are nerves that emerge directly from the brain in contrast to spinal nerves which emerge from segments of the spinal cord. ...

Sensory input is processed by the brain to recognize danger, find food, identify potential mates, and perform more sophisticated functions. Visual, touch, and auditory sensory pathways of vertebrates are routed to specific nuclei of the thalamus and then to regions of the cerebral cortex that are specific to each sensory system, the visual system, the auditory system, and the somatosensory system. Olfactory pathways are routed to the olfactory bulb, then to various parts of the olfactory system. Taste is routed through the brainstem and then to other portions of the gustatory system. In psychology, visual perception is the ability to interpret information from visible light reaching the eyes. ... Hearing (or audition) is one of the traditional five senses, and refers to the ability to detect sound. ... The thalamus (from Greek θάλαμος = bedroom, chamber, IPA= /ˈθæləməs/) is a pair and symmetric part of the brain. ... The human eye is the first element of a sensory system: in this case, vision, for the visual system. ... The visual system is the part of the nervous system which allows organisms to see. ... The auditory system is the sensory system for the sense of hearing. ... Touch redirects here. ... The olfactory system is the sensory system used for olfaction. ... Taste (or, more formally, gustation) is a form of direct chemoreception and is one of the traditional five senses. ... The gustatory system is the sensory system that uses taste buds (or lingual papillae) on the upper surface of the tongue to provide information about the taste of food being eaten. ...

To control movement the brain has several parallel systems of muscle control. The motor system controls voluntary muscle movement, aided by the motor cortex, cerebellum, and the basal ganglia. The system eventually projects to the spinal cord and then out to the muscle effectors. Nuclei in the brain stem control many involuntary muscle functions such as heart rate and breathing. In addition, many automatic acts (simple reflexes, locomotion) can be controlled by the spinal cord alone. To meet Wikipedias quality standards, this article or section may require cleanup. ... The cerebellum (Latin: little brain) is a region of the brain that plays an important role in the integration of sensory perception and motor control. ... The basal ganglia (or basal nuclei) are a group of nuclei in the brain interconnected with the cerebral cortex, thalamus and brainstem. ...

Brains also produce a portion of the body's hormones that can influence organs and glands elsewhere in a body—conversely, brains also react to hormones produced elsewhere in the body. In mammals, the hormones that regulate hormone production throughout the body are produced in the brain by the structure called the pituitary gland. For other uses, see Hormone (disambiguation). ... | Latin = hypophysis, glandula pituitaria | GraySubject = 275 | GrayPage = 1275 | Image = Gray1180. ...

Evidence strongly suggests that developed brains derive consciousness from the complex interactions between the numerous systems within the brain. Cognitive processing in mammals occurs in the cerebral cortex but relies on midbrain and limbic functions as well. Among "younger" (in an evolutionary sense) vertebrates, advanced processing involves progressively rostral (forward) regions of the brain. The limbic system is a historically defined set of brain structures that support a variety of functions including emotion and memory. ...

Hormones, incoming sensory information, and cognitive processing performed by the brain determine the brain state. Stimulus from any source can trigger a general arousal process that focuses cortical operations to processing of the new information. This focusing of cognition is known as attention. Cognitive priorities are constantly shifted by a variety of factors such as hunger, fatigue, belief, unfamiliar information, or threat. The simplest dichotomy related to the processing of threats is the fight-or-flight response mediated by the amygdala and other limbic structures. This article is about psychological concept of attention. ... The fight-or-flight response, also called hyperarousal or the acute stress response, was first described by Walter Cannon in 1915[1][2]. His theory states that animals react to threats with a general discharge of the sympathetic nervous system, priming the animal for fighting or fleeing. ... This article is about part of the human brain. ...

Neurotransmitter systems

Main article: Neurotransmitter systems

Neurons expressing certain types of neurotransmitters sometimes form distinct systems, where activation of the system causes effects in large volumes of the brain, called volume transmission. Neurotransmitter systems are systems of neurons in the brain expressing certain types of neurotransmitters, and thus form distinct systems. ...

The major neurotransmitter systems are the noradrenaline (norepinephrine) system, the dopamine system, the serotonin system and the cholinergic system. Norepinephrine, known as noradrenaline outside the USA, is a catecholamine and a phenethylamine with chemical formula C8H11NO3. ... For other uses, see Dopamine (disambiguation). ... For the professional wrestling stable, see Ravens Nest#Serotonin. ... A synapse is cholinergic if it uses acetylcholine as its neurotransmitter. ...

Drugs targeting the neurotransmitter of such systems affects the whole system, which explains the mode of action of many drugs;

• Cocaine, for example, blocks the reuptake of dopamine, leaving these neurotransmitters in the synaptic gap longer.
• Prozac is a selective serotonin reuptake inhibitor (SSRI), hence potentiating the effect of naturally released serotonin.
• AMPT prevents the conversion of tyrosine to L-DOPA, the precursor to dopamine; reserpine prevents dopamine storage within vesicles; and deprenyl inhibits monoamine oxidase (MAO)-B and thus increases dopamine levels.

Diseases may affect specific neurotransmitter systems. For example, Parkinson's disease is at least in part related to failure of dopaminergic cells in deep-brain nuclei, for example the substantia nigra. Treatments potentiating the effect of dopamine precursors have been proposed and effected, with moderate success. For other uses, see Cocaine (disambiguation). ... For other uses, see Dopamine (disambiguation). ... Illustration of the major elements in a prototypical synapse. ... Background Fluoxetine hydrochloride (brand names include Prozac®, Symbyax® (compounded with olanzapine), Sarafem®, Fontex® (Sweden), Fluctine (Austria, Germany), Prodep (India), Fludac (India)) is an antidepressant drug used medically in the treatment of depression, obsessive-compulsive disorder, bulimia nervosa, premenstrual dysphoric disorder, and many other disorders. ... Selective serotonin reuptake inhibitors (SSRIs) are a class of antidepressants. ... alpha-methyl-p-tyrosine (AMPT) is a drug that temporarily reduces brain catecholamine activity. ... // Therapeutic use L-DOPA is used to replace dopamine lost in Parkinsons disease because dopamine itself cannot cross the blood-brain barrierwhere its precursor can. ... Reserpine is an indole alkaloid antipsychotic and antihypertensive drug that has been used for the control of high blood pressure and for the relief of psychotic behaviors, although because of the development of better drugs for these purposes and because of its numerous side-effects, it is rarely used today. ... In cell biology, a vesicle is a relatively small and enclosed compartment, separated from the cytosol by at least one lipid bilayer. ... Selegiline/l-Deprenyl Selegiline (l-deprenyl, Eldepryl® or Anipryl® [veterinary]) is a drug used for the treatment of early-stage Parkinsons disease and senile dementia. ... Monoamine oxidase Monoamine oxidases (singular abbreviation MAO) (EC 1. ... The substantia nigra, (Latin for black substance, Soemering) or locus niger is a heterogeneous portion of the midbrain, separating the pes (foot) from the tegmentum (covering), and a major element of the basal ganglia system. ...

A brief comparison of the major neurotransmitter systems follows:

The Locus ceruleus, also spelled locus coeruleus, (Latin for the blue bit) is a nucleus in the brain stem apparently responsible for the physiological reactions involved in stress and panic. ... The tegmentum (from Latin for covering) is a general area within the brainstem. ... For other uses, see Dopamine (disambiguation). ... A neural pathway is a neural tract connecting one part of the nervous system with another, usually consisting of bundles of elongated, myelin insultated neurons, known collectively as white matter. ... The mesocortical pathway is a neural pathway which connects the ventral tegmentum to the cortex, particularly the frontal lobes. ... The mesolimbic pathway is one of the neural pathways in the brain that link the ventral tegmentum in the midbrain to the nucleus accumbens in the limbic system. ... The nigrostriatal pathway is a neural pathway which connects the substantia nigra with the striatum. ... The tuberoinfundibular pathway is a neural pathway which runs between the hypothalamus and the pituitary gland. ... Structure of a skeletal muscle Muscle is one of the four tissue types. ... Look up Cognition in Wiktionary, the free dictionary. ... The endocrine system is a control system of ductless endocrine glands that secrete chemical messengers called hormones that circulate within the body via the bloodstream to affect distant organs. ... For other uses, see Nausea (disambiguation). ... The dorsal raphe nucleus consists of rostral and caudal subdivisions. ... For the software company, see Introversion Software. ... A mood is a relatively lasting affective state. ... Satiety, or the feeling of fullness and disappearance of appetite after a meal, is a process mediated by the ventromedial nucleus in the hypothalamus. ... Thermoregulation is the ability of an organism to keep its body temperature within certain boundaries, even when temperature surrounding is very different. ... For other uses, see Sleep (disambiguation). ... Pain is both a sensory and emotional experience, generally associated tissue damage, or inflammation. ... The dorsal raphe nucleus consists of rostral and caudal subdivisions. ... Learning is the acquisition and development of memories and behaviors, including skills, knowledge, understanding, values, and wisdom. ... For other uses, see Memory (disambiguation). ... In the lateral part of the tuber cinereum is a nucleus of nerve cells, the basal optic nucleus of Meynert. ... The septal nuclei are structures in the middle anteroventral cerebrum that are composed of medium-size neurons grouped into medial, lateral, and posterior groups. ...

Origin

Since even unicellular organisms can have, at least, photosensitive eyespots and react to tactile stimuli, it is hypothesized that sensory organs developed before the brain did.^[7] The brain is an information-processing organ and its evolution is dependent on the presence of information accessed through sensory organs, sensory input, and the need to process this information and transmit it. Schematic representation of a Euglena cell with red eyespot (9) Schematic representation of a Chlamydomonas cell with chloroplast eyespot (4) The eyespot apparatus (or stigma) is a photoreceptive organelle found in the flagellate (motile) cells of green algae and other unicellular photosynthetic organisms such as euglenids. ...

Pathology

A human brain showing frontotemporal lobar degeneration causing frontotemporal dementia.

Clinically, death is defined as an absence of brain activity as measured by EEG. Injuries to the brain tend to affect large areas of the organ, sometimes causing major deficits in intelligence, memory, and movement. Head trauma caused, for example, by vehicle and industrial accidents, is a leading cause of death in youth and middle age. In many cases, more damage is caused by resultant edema than by the impact itself. Stroke, caused by the blockage or rupturing of blood vessels in the brain, is another major cause of death from brain damage. Image File history File links No higher resolution available. ... Image File history File links No higher resolution available. ... A human brain. ... Frontotemporal lobar degeneration (FTLD) is a form of dementia. ... For other uses, see Death (disambiguation). ... EEG can mean: Electroencephalography - the method and science of recording and interpreting traces of brain electrical activity as recorded from the skull surface or the device used to record such traces Emperor Entertainment Group - A Hong Kong entertainment company. ... This page is about the condition called edema. ... For other uses, see Stroke (disambiguation). ...

Other problems in the brain can be more accurately classified as diseases rather than injuries. Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, motor neurone disease, and Huntington's disease are caused by the gradual death of individual neurons, leading to decrements in movement control, memory, and cognition. Currently only the symptoms of these diseases can be treated. Mental illnesses, such as clinical depression, schizophrenia, bipolar disorder, and post-traumatic stress disorder are brain disorders that impact personality and, typically, other aspects of mental and somatic function. These disorders may be treated by psychiatric therapy, pharmaceutical intervention, or through a combination of treatments; therapeutic effectiveness varies significantly among individuals. Neurodegenerative disease (Greek νέυρο-, néuro-, nerval and Latin dēgenerāre, to decline or to worsen) is a condition in which cells of the brain and spinal cord are lost. ... The motor neurone diseases (MND) are a group of progressive neurological disorders that destroy motor neurones, the cells that control voluntary muscle activity such as speaking, walking, breathing, and swallowing. ... A mental illness or mental disorder refers to one of many mental health conditions characterized by distress, impaired cognitive functioning, atypical behavior, emotional dysregulation, and/or maladaptive behavior. ... On the Threshold of Eternity. ... For other uses, see Bipolar. ... Post-traumatic stress disorder (PTSD) is a term for certain severe psychological consequences of exposure to, or confrontation with, stressful events that the person experiences as highly traumatic. ... An MRI scan of a human brain and head. ... This article does not cite any references or sources. ...

Some infectious diseases affecting the brain are caused by viruses and bacteria. Infection of the meninges, the membrane that covers the brain, can lead to meningitis. Bovine spongiform encephalopathy (also known as mad cow disease), is deadly in cattle and humans and is linked to prions. Kuru is a similar prion-borne degenerative brain disease affecting humans. Both are linked to the ingestion of neural tissue, and may explain the tendency in some species to avoid cannibalism. Viral or bacterial causes have been reported in multiple sclerosis and Parkinson's disease, and are established causes of encephalopathy, and encephalomyelitis. This article is about biological infectious particles. ... Phyla Actinobacteria Aquificae Chlamydiae Bacteroidetes/Chlorobi Chloroflexi Chrysiogenetes Cyanobacteria Deferribacteres Deinococcus-Thermus Dictyoglomi Fibrobacteres/Acidobacteria Firmicutes Fusobacteria Gemmatimonadetes Lentisphaerae Nitrospirae Planctomycetes Proteobacteria Spirochaetes Thermodesulfobacteria Thermomicrobia Thermotogae Verrucomicrobia Bacteria (singular: bacterium) are unicellular microorganisms. ... The meninges (singular meninx) are the system of membranes that envelop the central nervous system. ... Meningitis is the inflammation of the protective membranes covering the central nervous system, known collectively as the meninges. ... Classic image of a cow with BSE. A notable feature of such disease is the inability (of the infected animal) to stand. ... For general information about the genus, including other species of cattle, see Bos. ... For the bird, see Prion (bird). ... Kuru (also known as laughing sickness due to the outbursts of laughter that mark its second phase) was first noted in New Guinea in the early 1900s. ... Cannibal redirects here. ... Encephalopathy literally means disease of the brain. ... Encephalomyelitis is a general term for inflammation of the brain and spinal cord, describing a number of disorders: acute disseminated encephalomyelitis or postinfectious encephalomyelitis, a demyelinating disease of the brain and spinal cord, possibly triggered by vaccination or viral infection; encephalomyelitis disseminata, a synonym for multiple sclerosis; equine encephalomyelitis, a...

Many brain disorders are congenital. Tay-Sachs disease, Fragile X syndrome, and Down syndrome are all linked to genetic and chromosomal errors. Many other syndromes, such as the intrinsic circadian rhythm disorders, are suspected to be congenital as well. Malfunctions in the embryonic development of the brain can be caused by genetic factors, drug use, nutritional deficiencies, and disease during a mother's pregnancy. A congenital disorder is any medical condition that is present at birth. ... Tay-Sachs disease (abbreviated TSD, also known as GM2 gangliosidosis, Hexosaminidase A deficiency or Sphingolipidosis) is a genetic disorder, fatal in its most common variant known as Infantile Tay-Sachs disease. ... Fragile X syndrome is a syndrome of X-linked mental retardation. ... For other uses, see Gene (disambiguation). ... For information about chromosomes in genetic algorithms, see chromosome (genetic algorithm). ... A circadian rhythm is a roughly-24-hour cycle in the physiological processes of living beings, including plants, animals, fungi and cyanobacteria. ... The study of neural development draws on both neuroscience and developmental biology to describe the cellular and molecular mechanisms by which complex nervous systems emerge during embryonic development and throughout life. ... Recreational drug use is the use of psychoactive drugs for recreational rather than medical or spiritual purposes, although the distinction is not always clear. ... Many diseases in humans are thought to be directly or indirectly related to nutrition, These include, but are not limited to, deficiency diseases, caused by a lack of essential nutrients. ... This article is about the medical term. ... This article is about human pregnancy in biological females. ...

Certain brain disorders are treated by brain neurosurgeons while others are treated by neurologists and psychiatrists. Neurosurgery is the surgical discipline focused on treating the central and peripheral nervous system. ...

Study of the brain

Fields of study

Neuroscience seeks to understand the nervous system, including the brain, from a biological and computational perspective. Psychology seeks to understand behavior and the brain. Neurology refers to the medical applications of neuroscience. The brain is also one of the most important organs studied in psychiatry, the branch of medicine which exists to study, prevent, and treat mental disorders.^[8][9][10] Cognitive science seeks to unify neuroscience and psychology with other fields that concern themselves with the brain, such as computer science (artificial intelligence and similar fields) and philosophy. Drawing of the cells in the chicken cerebellum by S. Ramón y Cajal Neuroscience is a field that is devoted to the scientific study of the nervous system. ... Computational neuroscience is an interdisciplinary science that links the diverse fields of neuroscience, cognitive science, electrical engineering, computer science, physics and mathematics. ... {redirect|Psychological science|the journal|Psychological Science (journal)}} Not to be confused with Phycology. ... Neurology is a branch of medicine dealing with disorders of the nervous system. ... For the chemical substances known as medicines, see medication. ... An MRI scan of a human brain and head. ... The Scream, the famous painting commonly thought of as depicting the experience of mental illness. ... Cognitive science is usually defined as the scientific study either of mind or of intelligence (e. ... Computer science, or computing science, is the study of the theoretical foundations of information and computation and their implementation and application in computer systems. ... AI redirects here. ... For other uses, see Philosophy (disambiguation). ...

Methods of observation

Main article: neuroimaging

Each method for observing activity in the brain has its advantages and drawbacks. It has been suggested that this article or section be merged with functional neuroimaging. ...

Electrophysiology

Electrophysiology allows scientists to record the electrical activity of individual neurons or groups of neurons.

EEG

By placing electrodes on the scalp one can record the summed electrical activity of the cortex in a technique known as electroencephalography (EEG). EEG measures the mass changes in electrical current from the cerebral cortex, but can only detect changes over large areas of the brain with very little sub-cortical activity. EEG redirects here. ...

MEG

Apart from measuring the electric field around the skull it is possible to measure the magnetic field directly in a technique known as magnetoencephalography (MEG). This technique has the same temporal resolution as EEG but much better spatial resolution, although admittedly not as good as fMRI. The main advantage over fMRI is a direct relationship between neural activation and measurement. Magnetoencephalography (MEG) is the measurement of the magnetic fields produced by electrical activity in the brain, usually conducted externally, using extremely sensitive devices such as SQUIDs. ...

fMRI and PET

A scan of the brain using fMRI

Functional magnetic resonance imaging (fMRI) measures changes in blood flow in the brain, but the activity of neurons is not directly measured, nor can it be distinguished whether this activity is inhibitory or excitatory. fMRI is a noninvasive, indirect method for measuring neural activity that is based on BOLD; Blood Oxygen Level Dependent changes. The changes in blood flow that occur in capillary beds in specific regions of the brain are thought to represent various neuronal activities (metabolism of synaptic reuptake). Similarly, a positron emission tomography (PET), is able to monitor glucose and oxygen metabolism as well as neurotransmitter activity in different areas within the brain which can be correlated to the level of activity in that region. Sample fMRI data This example of fMRI data shows regions of activation including primary visual cortex (V1, BA17), extrastriate visual cortex and lateral geniculate body in a comparison between a task involving a complex moving visual stimulus and rest condition (viewing a black screen). ... Sample fMRI data This example of fMRI data shows regions of activation including primary visual cortex (V1, BA17), extrastriate visual cortex and lateral geniculate body in a comparison between a task involving a complex moving visual stimulus and rest condition (viewing a black screen). ... Blood flow is the flow of blood in the cardiovascular system. ... Structure of the coenzyme adenosine triphosphate, a central intermediate in energy metabolism. ... Image of a typical positron emission tomography (PET) facility Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three-dimensional image or map of functional processes in the body. ... Glucose (Glc), a monosaccharide (or simple sugar), is an important carbohydrate in biology. ... This article is about the chemical element and its most stable form, or dioxygen. ...

Behavioral

Behavioral tests can measure symptoms of disease and mental performance, but can only provide indirect measurements of brain function and may not be practical in all animals. In humans however, a neurological exam can be done to determine the location of any trauma, lesion, or tumor within the brain, brain stem, or spinal cord. Skin lesions caused by Chickenpox A lesion is any abnormal tissue found on or in an organism, usually damaged by disease or trauma. ... For malignant tumors specifically, see cancer. ...

Anatomical

Autopsy analysis of the brain allows for the study of anatomy and protein expression patterns, but is only possible after the human or animal is dead. Magnetic resonance imaging (MRI) can be used to study the anatomy of a living creature and is widely used in both research and medicine. The term post mortem means after death. It is also short for postmortem examination, or autopsy. ... A representation of the 3D structure of myoglobin showing coloured alpha helices. ... MRI redirects here. ...

Other studies

Computer scientists have produced simulated "artificial neural networks" loosely based on the structure of neuron connections in the brain. Some artificial intelligence research seeks to replicate brain function—although not necessarily brain mechanisms—but as yet has been met with limited success. Computer science, or computing science, is the study of the theoretical foundations of information and computation and their implementation and application in computer systems. ... An artificial neural network (ANN), often just called a neural network (NN), is a mathematical model or computational model based on biological neural networks. ... AI redirects here. ...

Creating algorithms to mimic a biological brain is very difficult because the brain is not a static arrangement of circuits, but a network of vastly interconnected neurons that are constantly changing their connectivity and sensitivity. More recent work in both neuroscience and artificial intelligence models the brain using the mathematical tools of chaos theory and dynamical systems. Current research has also focused on recreating the neural structure of the brain with the aim of producing human-like cognition and artificial intelligence. Flowcharts are often used to graphically represent algorithms. ... For other meanings of mathematics or uses of math and maths, see Mathematics (disambiguation) and Math (disambiguation). ... For other uses, see Chaos Theory (disambiguation). ... The Lorenz attractor is an example of a non-linear dynamical system. ...

As food

Goat brain prior to being cooked

Like most other internal organs, the brain can serve as nourishment. For example, in the Southern United States canned pork brain in gravy can be purchased for consumption as food. This form of brain is often fried with scrambled eggs to produce the famous "Eggs n' Brains".^[11] The brain of animals also features in French cuisine such as in the dish tête de veau, or head of calf. Although it sometimes consists only of the outer meat of the skull and jaw, the full meal includes the brain, tongue, and glands. Similar delicacies from around the world include Mexican tacos de sesos made with cattle brain as well as squirrel brain in the US South.^[12] The Anyang tribe of Cameroon practiced a tradition in which a new tribal chief would consume the brain of a hunted gorilla while another senior member of the tribe would eat the heart.^[13] Indonesian cuisine specialty in Minangkabau cuisine also served beef brain in a gravy coconut milk named gulai otak (beef brain curry). Roasted or fried goat brain is eaten in south India and some parts of north India. Norwegian cuisine includes smalahove where a singed lamb's head, including the brain, tongue and eye, serves two people. Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 107 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Image File history File links Metadata Size of this preview: 800 × 600 pixelsFull resolution (1024 × 768 pixel, file size: 107 KB, MIME type: image/jpeg) File historyClick on a date/time to view the file as it appeared at that time. ... Historic Southern United States. ... For other uses, see Pork (disambiguation). ... For other uses, see Gravy (disambiguation). ... Scrambled eggs Scrambled eggs is a dish made from beaten whites and yolks of eggs (usually chicken). ... Eggs n Brains is a breakfast meal consisting of pork brains and scrambled eggs. ... A pot of coq au vin, a well-known French dish French cuisine is a style of cooking derived from the nation of France. ... Human jaw front view Human jaw left view Human jaw top view The jaw is either of the two opposable structures forming, or near the entrance to, the mouth. ... For other uses, see Tongue (disambiguation). ... Human submaxillary gland. ... For other uses, see Taco (disambiguation). ... This article is about the animal. ... The examples and perspective in this article may not represent a worldwide view. ... For other uses, see Gorilla (disambiguation). ... http://www. ... Languages Minangkabau, Indonesian and Malay. ... Smalahove (or smalehovud) is a Norwegian traditional dish, usually eaten around and before Christmas time, made from a sheeps head. ...

Consuming the brain and other nerve tissue of animals is not without risks. The first problem is that the makeup of the brain is 60% fat due to the myelin (which itself is 70% fat) insulating the axons of neurons and glia.^[14] As an example, a 140 g can of "pork brains in milk gravy", a single serving, contains 3500 milligrams of cholesterol, 1170% of our recommended daily intake.^[15] Myelin is an electrically insulating phospholipid layer that surrounds the axons of many neurons. ... Cholesterol is a sterol (a combination steroid and alcohol). ...

Brain consumption can result in contracting fatal transmissible spongiform encephalopathies such as Variant Creutzfeldt-Jakob disease and other prion diseases in humans and mad cow disease in cattle.^[16] Another prion disease called kuru has been traced to a funerary ritual among the Fore people of Papua New Guinea in which those close to the dead would eat the brain of the deceased to create a sense of immortality.^[17] Some archaeological evidence suggests that the mourning rituals of European Neanderthals also involved the consumption of the brain.^[18] Because of the risk of being infected by prions one should always wear gloves when handling brains. Transmissible spongiform encephalopathies (TSEs, also known as prion diseases) are a group of progressive conditions that affect the brain and nervous system of humans and animals and are transmitted by prions. ... Creutzfeldt-Jakob disease (CJD) is a very rare and incurable degenerative neurological disorder (brain disease) that is ultimately fatal. ... For the bird, see Prion (bird). ... Classic image of a cow with BSE. A notable feature of such disease is the inability (of the infected animal) to stand. ... Kuru (also known as laughing sickness due to the outbursts of laughter that mark its second phase) was first noted in New Guinea in the early 1900s. ... The Fore are a highland people of Papua New Guinea. ... The Fountain of Eternal Life in Cleveland, Ohio Immortality (or eternal life) is the concept of living in physical or spiritual form for an infinite length of time, or in a state of timelessness. ... For referencing in Wikipedia, see Wikipedia:Citing sources. ... For other uses, see Europe (disambiguation). ... For other uses, see Neanderthal (disambiguation). ...

It is also well-known in the hunting community that the brain of wild animals should not be consumed, due to the risk of chronic wasting disease. The brain is still useful to hunters, in that most animals have enough brain matter for use in the tanning of their own hides. Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy (TSE) of deer, elk (wapiti), and moose. ... This article is about making hides into leather. ...

Brain energy consumption

PET Image of the human brain showing energy consumption

Although the brain represents only 2% of the body weight, it receives 15% of the cardiac output, 20% of total body oxygen consumption, and 25% of total body glucose utilization. The energy consumption for the brain to simply survive is 0.1 calories per minute, while this value can be as high as 1.5 calories per minute during crossword puzzle-solving.^[19] The demands of the brain limit its size in many species. Molossid bats and the Vespertilionid Nyctalus spp. have brains that have been reduced from the ancestral form to invest in wing-size for the sake of maneuverability. This contrasts with fruit bats, which require more advanced neural structures and do not pursue their prey.^[20] ImageMetadata File history File links PET-image. ... ImageMetadata File history File links PET-image. ... Image of a typical positron emission tomography (PET) facility Positron emission tomography (PET) is a nuclear medicine medical imaging technique which produces a three-dimensional image or map of functional processes in the body. ... The Free-tailed bats in the family Molossidae are generally quite robust and consist of many strong flying forms with relatively long and narrow wings. ... Evening bats or perhaps more correctly Vesper bats (family Vespertilionidae) are the largest and best-known family of bats. ... The bat genus Nyctalus (Noctule bats) are members of the family Vespertilionidae (Vesper bats) or sometimes Evening bats. ... It has been suggested that this article or section be merged with megabats. ...

Neuroscience Portal

Image File history File links No higher resolution available. ...

Further reading

• Junqueira, L.C., and J. Carneiro (2003). Basic Histology: Text and Atlas, Tenth Edition. Lange Medical Books McGraw-Hill. ISBN 0-07-121565-4. 
• Kinseher Richard, Geborgen in Liebe und Licht – Gemeinsame Ursache von Intuition, Déjà-vu-, Schutzengel-, und Nahtod-Erlebnissen, BoD, 2006, ISBN 3-8334-51963, German language: (A new theory: A LIVE-scan of the episodic memory, can be observed during near-death-experiences. The stored experiences are then judged by the topical intellect.)
• Sala, Sergio Della, editor. (1999). Mind myths: Exploring popular assumptions about the mind and brain. J. Wiley & Sons, New York. ISBN 0-471-98303-9. 
• Vander, A., J. Sherman, D. Luciano (2001). Human Physiology: The Mechanisms of Body Function. McGraw Hill Higher Education. ISBN 0-07-118088-5. 
• Scaruffi, Piero. The Nature of Consciousness. Omniware. ISBN 0-9765531-1-2. 

This article or section cites very few or no references or sources. ...

References

• Doidge, Norman (2007-03-15). The Brain That Changes Itself: Stories of Personal Triumph from the Frontiers of Brain Science. Viking Adult. 

Eric Richard Kandel (born November 7, 1929) is a psychiatrist, a neuroscientist and professor of biochemistry and biophysics at Columbia University. ... Principles of Nerual Science cover First published in 1981, Principles of Neural Science is a neuroscience textbook edited by Eric R. Kandel, James Schwartz, and Thomas Jessell. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... 2008 (MMVIII) is the current year, a leap year that started on Tuesday of the Anno Domini (or common era), in accordance to the Gregorian calendar. ... is the 116th day of the year (117th in leap years) in the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... Year 2005 (MMV) was a common year starting on Saturday (link displays full calendar) of the Gregorian calendar. ... A digital object identifier (or DOI) is a standard for persistently identifying a piece of intellectual property on a digital network and associating it with related data, the metadata, in a structured extensible way. ... Year 2007 (MMVII) was a common year starting on Monday of the Gregorian calendar in the 21st century. ... is the 154th day of the year (155th in leap years) in the Gregorian calendar. ... Biology Letters Biology Letters (ISSN 1744-9561) is a largely online published journal covering a wide spectrum of biological sciences. ...

External links

Wikimedia Commons has media related to:

Brain

• How Your Brain Works at HowStuffWorks
• The HOPES Brain Tutorial at hopes.stanford.edu
• Comparative Mammalian Brain Collection
• Brain Research News from ScienceDaily
• BrainInfo for Neuroanatomy
• Neuroscience for kids
• Everything you wanted to know about the brain – Provided by New Scientist.
• Fact sheets on brain injury - causes, effects and coping strategies
• Neuroscience wiki.
• BrainMaps.org, interactive high-resolution digital brain atlas based on scanned images of serial sections of both primate and non-primate brains
• Scientific American Magazine (September 2003 Issue) Ultimate Self-Improvement
• Brain Research and Information Network B.R.A.I.N.

The dorsal repiratory group is found in many types of fish and marine mammals. ... The ventral respiratory group is a group of neurons in the medulla which initiates inhalation. ... The interior district of the medulla oblongata is named the pyramid and lies between the anterior median fissure and the antero-lateral sulcus. ... The two pyramids contain the motor fibers which pass from the brain to the medulla oblongata and medulla spinalis, corticobulbar and corticospinal fibers. ... In anatomy, the olivary bodies or simply olives (Latin oliva) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. ... The olivocerebellar tract (olivocerebellar fibers) leaves the olivary nucleus and pass out through the hilum and decussate with those from the opposite olive in the raphé, then as internal arcuate fibers they pass partly through and partly around the opposite olive and enter the inferior peduncle to be distributed to... The anterior median fissure (ventral or ventromedian fissure) contains a fold of pia mater, and extends along the entire length of the medulla oblongata: it ends at the lower border of the pons in a small triangular expansion, termed the foramen cecum. ... Certain of the cranial nerves pass through the substance of the medulla oblongata, and are attached to its surface in series with the roots of the spinal nerves; thus, the fibers of the hypoglossal nerve represent the upward continuation of the anterior nerve roots, and emerge in linear series from... Grays Fig. ... In anatomy, the olivary bodies or simply olives (Latin oliva and olivae, singular and plural, respectively) are a pair of prominent oval structures in the medulla oblongata, the lower portion of the brainstem. ... The reticular formation is a part of the brain which is involved in stereotypical actions, such as walking, sleeping, and lying down. ... The gigantocellular nucleus, as the name indicates, is mainly composed of the so called giant neuronal cells. ... The parvocellular reticular nucleus is located dorsolateral to the nucleus reticularis pontis caudalis. ... The ventral reticular nucleus is a continuation of the parvocellular nucleus in the brainstem. ... A nucleus of the medulla oblongata involved with co-ordinating baroreceptor signals to control arterial blood pressure. ... The paramedian reticular nucleus (in Terminologia Anatomica, or paramedian medullary reticular group in NeuroNames) sends its connections to the spinal cord in a mostly ipsilateral manner, although there is some decussation. ... The raphe nuclei (Latin for the bit in a fold or seam) is a moderately sized cluster of nuclei found in the brain stem, and releases serotonin to the rest of the brain. ... The nucleus raphe obscurus, despite the implications of its name, has some very specific functions and connections of afferent and efferent nature. ... The nucleus raphe magnus, located directly rostral to the raphe obscurus, is afferently stimulated from axons in the spinal cord and cerebellum. ... The nucleus raphe pallidus receives afferent connections from the periaqueductal gray, the paraventricular hypothalamic nucleus, central nucleus of the amygdala, lateral hypothalamic area, and parvocellular reticular nucleus. ...