Brain

Größenvergleich der Gehirne verschiedener SäugetiereQuelle: University of Wisconsin and Michigan State Comparative Mammalian Brain Collections and the National Museum of Health and Medicine.
size comparison of the brains of different mammals
source: University OF Wisconsin and Michigan State Comparative Mammalian Brain Collections and the national museum OF Health and Medicine.

Brain (brain, Cerebrum, Encephalon) one calls the part lain in the head of the Central nervous system (ZNS) of the vertebrate animals. It lies protected in the head cave and coated from the brain skin.

Table of contents

function

the vertebrate animal brain finished high-centralizes sensory impressions and coordinates complex behaviors. Itis thus the main integration place for all critical information, which is processed in an organism.

However each information up to the brain cortex does not arrive and thus at consciousness. Above all peripheral lying nerve networks (Plexus) and centers in the brain stem serveunconscious preprocessing of signals.Reflex elbows take over tasks, which must run off with highest speed and without conscious processing and retarding influencing control. Also with humans is such a autonomous nervous system. It serves the co-ordination of vegetative functions such as respiration, cycle(Heart function), food intake, - digesting and - delivery, Flüssigkeitsaufnahme and - elimination, as well as the reproduction. The regularization of these processes would make excessive demands of and with it would block those structures of the brain, which are busy with the conscious perception, completely.

The function of the brain is based mainlyon the interaction of strongly interlaced neurons over electrical impulses (see neural net). A means to the analysis of brain activities represents therefore the measurement of the brain stream by means of a EEG . Another method of the measurement is the MEG.

InRun of the evolution reached the brain of higher animals a considerable measure of differentiation and internal organization (Zerebration). The structure and - in smaller measure - which know size of the brain as reference point for the adaptability and intelligencean animal to be consulted. Again the brain is not alone to learning achievements able, neural plasticity is on as good as all hierarchic levels of the nervous system.

Beside the vertebrate animals also Tintenfische possess high-complex brains, them to purposeful activitiesenable. In the broader sense one calls therefore also the central office of the nervous system of different eddyless animals, for instance the Ringelwürmer or insects, brain. Depending upon type of brain one speaks here of Cerebralganglion, upper throat ganglion etc.




structurethe vertebrate animal brain

Magnetresonanztomografieaufnahmen eines menschlichen Gehirns

the human brain

a human brain
MRT-Bild eines menschlichen Gehirns. Schnitt sagittal, die Nase ist links. Hier klicken für eine animierte Abfolge von Schnitten.
March - picture of a human brain. Cut sagittal, the nose is left. Here click for an animated succession of cuts.

The human brain(beside simple nervous systems of some worms, as well as the brains of mice, rats, as well as cats and Primaten ) the best examined brain is in the animal realm, nevertheless is still many questions unsettled.

summary of the structure of the humanBrain

one differentiates simplifies 4 prime data areas:

a) The grosshirn is divided in the center by a cut into two hemispheres (= hemispheres). These are folded strong or also gefurcht. There is a broad connection between the hemispheres, whatever Bar is called - it concerns thereby a thick nerve strand. In addition further smaller connections exist.

The 2-4mm thick surface is called cerebral cortex. It contains approx. 14 billion Somata of nerve cells. Thus it appears grey and becomes thereforealso grey substance mentioned.

On it the crust fields in such a way specified can be located. One differentiates between primary fields and association fields. First process excluding information of a quality. These are either information about perceptions (feeling, z. B. See, a smelling, contact, etc.) orover movements (simple movements). The latters co-ordinate different functions. Importantly to note it is that an individual crust field is not responsible for a function alone, but that correct interaction in a network from different nerves, those from different fieldscome, only a complete function made possible.

To the primary fields one counts for example the visual Cortex, on which the projections of the Sehbahn flow. It is because of the rear pole of the brain. Another example is the auditorische Cortex, thatserves the processing of acoustic attractions and laterally in the sleep rag is.

One finds associative fields for example in the front part of the brain. To these tasks come such as memory and higher thinking procedures.

The position of the crust fields became by losses (howe.g. according to impact accumulations), determines investigations with electrical Stimulation, microscopic and other techniques.

Inside the grosshirns is the white substance. In this run axons, which connects the individual parts of the grosshirns with other parts of the nervous system.

b) At the Kleinhirn likewise two hemispheres can be differentiated. Additionally one defines still further parts. It e.g. is. responsible for equilibrium , movements and their co-ordination. With animals the Kleinhirn is often relative to the grosshirn more strongly pronounced than withHumans, in particular with animals with Flugvermögen or with fast robbers.

Apart from the automated courses of motion also a function is attributed to the Kleinhirn when unconscious learning. Newer research (2005) suggests that it also a portion of the language acquisition and thatsocial learning has.

c) To the Zwischenhirn one counts 4 parts:

  1. Thalamus (top)
  2. hypothalamus, which is connected with the hypophysis (pituitary gland).
  3. Subthalamus
  4. Epithalamus

of the Thalamus is the intermediary from sensitive and motor signals to and from the grosshirn. With itgathers all information of the sensory organs, and becomes far mediating. Mainly the Thalamus consists of grey substance. The hypothalamus steers numerous physical and psychological life procedures and becomes even partly nerve hormoneal over the vegetative nervous system and partly over the blood waysteered.Hypothalami and hypophysis (important hormone gland of the body, which is connected with the hypothalamus by the hypophysis handle) are the central link between the hormone system and the nervous system. The Zwischenhirn is among other things responsible for the sleep - wax price increase, pain sensation and Temperature regularization.

d) The brain stem is the masterhistorically oldest range of the brain. It forms the lowest brain section and consists of ascend and for descending nerve fibers (white substance) and of accumulations of neurons and/or. of Somata (grey substance).It consists of the central brain, which bridge (Pons) as well as the Nachhirn (also extended Mark = Medulla oblongata mentioned, there it between bridge (Pons) and back Mark is). The brain stem interconnects and processes detailed sensory impressions and outgoing motor information andis besides for elementary and reflex-like Steuermechanismen responsibly.

In the Nachhirn the nerve courses of the two body halves cross. In addition many procedures automatically running off are steered here such as heart impact , respiration or metabolism. Likewise are here important reflex centers, so that e.g. Eyelid conclusion, sip, cough - and other reflexes to be released. The lower end of the Nachhirns attaches to back Mark .

the brain of an adult woman

weighs brains of men and Mrs. Durchschnittlich 1245 g, an adultMan 1375 G. Between man and woman no significant differences are to be determined regarding intelligence despite these differences in weight.

In principle there are many differences in the structure and function mode of the brain between men and women. Sex hormones like the Östrogene and Testosteron worknot only on the gonads, but in various way on the nervous system as a whole and nerve cells, synapses, Genexpression etc. in detail both during the Embryonalentwicklung, and during childhood and puberty as well as at the adult age. Examples of it are inComparison to women with young men increased Regio praeoptica in the hypothalamus. Recently with modern picture-giving procedures it was measured that during the presented rotation of three-dimensional objects with men a brain region shows increased activity, with Mrs. two.

In popular-scientific publicationslately the terms system - brain (S-brain) and Empathie - emerged brain (E-brain), whereby first is attributed above all to men and the latter women.

achievement of the brain

the brain is a very active organ and has oneenormous oxygen - and power requirement. So must be pumped about 20% of the blood (heart minute volume) by the heart to the brain. Since it possesses only extremely small storage capacities, the brief loss of the blood supply leads to brain damage.

The historical erring faith, Genialitätmust be readable at (after death taken) the brain, is as old as the brain research and even today still occasionally one continues. The special book author Michael Hagner supplied and. A. on the basis the brain characteristics of many personalities such as Immanuel Kant, Vladimir IljitschLenin or Albert Einstein beside a history of the brain research as well as topic-referred views of the culture and social history of the past three centuries. Not few brain researchers came thereby also into the driving water of nationalistic and volume-gravel-CH-racistic thinking.

Often comparisons between the efficiency become one Computer and that of the human brain employed. In former times one tried also to judge from the function mode of computers the function mode of the brain. Today against it one tries in neuro computer science to partly copy the function mode of the brain on computers and/or.to come by these on new ideas to the “intelligent” data processing. As structure for thinking and knowledge production the brain supplies an architecture, which is recommended for imitation.Artificial neural networks were already established at the organization of artificial intelligence processes.

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Konnektivität

the human brain possesses estimations to consequence approx. 100 billion (10 11) nerve cells, which through approx. 100 trillion (10 14) synapses are closely connected. That is, that each neuron on average with 1000 othersNeurons and thus in principle any neuron from each starting neuron is connected in at the most 4 steps is attainable. However there are locally clear deviations from this average value [1]. Admits is also the retinotrope illustration characteristic.

Olfactorius - smelling makes

  1. Nervus possible opticus - optical impulses Nervus
  2. lead the 12 pairs of main nerves of the brain
  3. Nervus oculomotorius - supplies 4 of 6 muscles, which move the eye, among other things Functions
  4. Nervus trochlearis - supplies the upper diagonal eye muscle
  5. Nervus trigeminus - leads among other things Information about contacts from the face range
  6. for Nervus abducens - Nervus supplies the lateral
  7. eye muscle facialis - makes possible among other things mimische movements and taste perception
  8. Nervus vestibulocochlearis (N. statoacusticus) - leads information from the hearing and thatOrgan of equilibrium
  9. Nervus glossopharyngeus - among other things it leads information (also taste) from the throat range and makes for movements possible within this range
  10. Nervus vagus - perception and movement - inclusive gland activity and hormone payment of a part of entrails
  11. Nervus accessorius - movement makes possible intwo large muscles of the neck and head
  12. Nervus hypoglossus - movements for the tongue possible [
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also Konnektivität

literature

  • Olaf Breidbach: The Materialisierung of the Ichs: ToHistory of the brain research in 19. and 20. Century. Frankfurt A.M.: Suhrkamp, 1997. (stw; 1276). ISBN 3-518-28876-8
  • Günter lanes, Sabine Minol: Unknown nature brain. Darmstadt: Media team publishing house, 2004. ISBN 3-932845-71-4
  • Eccles, John C.: Like the evenits brain steers. Berlin/Heidelberg: Springer, 1994
  • Michael Hagner: Ingenious brains. To the history of the elite brain research. Goettingen: Barrier stone, 2004. ISBN 3-8924-4649-0
  • Sabine Perl, Verena Weimer, Hans Günter lanes: The brain: Between perfection and disaster. Biology in oursTime 33 (1), S. 36-44 (2003), ISSN 0045-205X
  • John von Neumann: Computer and the Brain. Yale University press, 2000. ISBN 0300084730
  • smelling pool of broadcasting corporations F. Thompson: The brain: from the nerve cell to the behavior control. Heidelberg: Spectrum academic publishing house, 2001 (3.Aufl.) ISBN 3-8274-1080-0

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Wiktionary: Brain - word origin, synonyms and translations
Wikiquote: Brain - quotations

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