The structure of human brain, mainly including brainstem, cerebellum andthe forebrainThree parts.
Human brain structure
brainstem(brainstem) upper bearingCerebral hemisphereIt is connected to the spinal cord in an irregular columnar shape.Transmitted to the brain via the spinal cordNerve impulse, enter in a cross way: impulses from the right side of the spinal cord are transmitted to the left side of the brain stem first, and then to the brain;Those from the left side of the spinal cord are sent to the right side of the brain stem first, and then to the brain.The function of brain stem is mainly to maintain individual life, including heartbeat, respiration, digestion, body temperature, sleep, etcphysiological function, all related to the function of brain stem.
The brain stem also includes the following four important structures:
1．Medulla oblongata(medulla) The medulla oblongata is located at the bottom of the brain and connected with the spinal cord;Its main function is to control breathing, heartbeat, digestion, etc.
2．PonsPonsmidbrainAndMedulla oblongatabetween.Pontinewhite matternerve fiber, access toCerebellar cortexIt can transfer nerve impulses from one hemisphere of the cerebellum to the other half of the ball, so that it can play the role of coordinating the activities of muscles on both sides of the body.
3．midbrainThe midbrain is located above the pons, which is just the midpoint of the whole brain.The midbrain is visual and auditoryReflex centerAll activities of pupils, eyeballs and muscles are controlled by the midbrain.
4．Reticular systemThe reticular system is located in the center of the brain stem and is composed of many intricateneuronAssembledReticular structure。The main function of the reticular system is to control different levels of arousal, attention, sleep, etcState of consciousness。
Cerebellum is located in the brain andOccipital lobeBelow, just belowbrainstemBehind is the second part of the brain.The cerebellum is composed of left and right hemispheres, with gray matter outside and white matter inside.In terms of function, cerebellum andCerebral cortexExercisejoint controlMuscle movement can adjust the balance between posture and body.
1. The thalamus is oval, composed of white matter nerve fibers, one on the left and one on the right, located below the parallel corpus callosum.The nerve impulses transmitted from the spinal cord, brain stem and cerebellum all terminate at the optic thalamus first, and then transmit to the relevant areas of the cerebral cortex through the optic thalamus.So the hypothalamus issensory nerveImportant transfer station.In addition, the hypothalamus also has the function of controlling emotions.
2. The hypothalamus is located below the hypothalamusautonomic nervous systemIt is the main control center of the brain, which is directly connected with various regions in the brainthe pituitaryAnd the medulla oblongata.The main function of the hypothalamus is to controlendocrine systemMaintain normal metabolism, regulate body temperature, and interact with hunger, thirst, sex, etc. in physiological activitiesPhysiological motivationThere is a close relationship.
3．Limbic systemThe limbic system is generally considered to include the hypothalamus, hypothalamus and midbrain.The main functions of the limbic system are smell, visceraautonomic nerveEndocrine, sexual, feeding, learning, memory, etc.The edge system has twoNervous tissue, i.eamygdalaWith hippocampus, the former is related to emotional performance, and the latter is related to memory.
4．cerebral cortex(cerebra cortex) is the surface layer of the brain, which is composed of gray matter. Its thickness is about 1 to 4mm, and most of its lower part is composed ofwhite matterComposition.There's a fissure in the middle of the brain（Longitudinal cerebral fissure，longitudinal fissure），The brain is divided into left and right hemispheres from front to back, calledCerebral hemisphere（cerebral hemisphere）。Between two hemispherescorpus callosum(corpus collosum) to connect the two hemispheresnerve conductionTo communicate with each other.
Ten brain characteristics you should know
1. The brain does not feel pain
Although it is responsible for processing signals from other parts of the body, the brain is strangely unable to feel pain.(The feeling of pain needs to bereceptor，Afferent nerve, nerve center,Efferent nerve，EffectorCooperation is generated, and the brain is a nerve center, which has no effector in itself, so it cannot sense pain).
Several studies have concluded that stress has a negative impact on our brain and can reduce brain volume.
3.15W
The adult brain consumes only 250-300 kcal a day.In other words, the power of a brain weighing between 1300-1400 grams (the average weight of an adult brain) is about 15 watts.The energy consumed by the brain is equivalent to that of two large bananas.Although not a lot, compared with the total energy consumed by the body, it is indeed a lot, because the power of the fully operating body is only 70 watts.
4. Thousands of kilometers longnerve cellAnd endless nerve regeneration
It is estimated that the human brain has 100 billion nerve cells. If they are arranged in a straight line, the length will reach 1000 kilometers.However, because nerve cells are highly differentiated cells, they cannot regenerate.But physical exercise can stimulate the creativity of the brain.
5. Cut off and transformation
The baby will cut off the nerve connections he does not need, that is, cut off those unnecessary nerve connections in the first two years of life.At the same time, during adolescence, not only the body structure will change, but alsoMode of thinkingWill change becausebrainThe structure has been completely changed.
6. Excitement at night and fatigue will stimulate creativity
When other parts of the body reduce activity (the minimum amount of activity will be reached during sleep), but the amount of brain activity will increase, so in most cases, the amount of brain activity during sleep is greater than that during waking.Because the activities carried out when staying up late and those carried out when sleeping will activate different regions of the brain.What is more surprising is that the tired brain has stronger creativity.
7. Gender
It is well known that there are differences between men and women, and the male brain and the female brain also have different ways of working.In fact, men and women are different in the choice of space, and women need more references in the choice of routes.For example, most men will say, turn right after 500 meters, and then turn left after 1000 meters;Generally speaking, women prefer to turn right at the red high-rise building, and then turn left when they meet a flower shop.
The nerve cells in the brain are arranged in different forms and transmit information at different speeds.This is why sometimes we can think of something quickly, and sometimes it takes a while to remember it.
9. More and more happiness
As the brain ages, people will more easily control their emotions and better digest negative thoughts.So, as time goes by, ourHappinessWill become higher.
10. The higher IQ, the less sleep
The higher a person's IQ, the less sleep he gets.In addition,High IQIt can resist mental illness.There is even another situation, that is, a person with high IQ is clearly sleeping, but in fact he is awake.
Research findings
Announce
edit
Scientists before the 19th century thought that the brain's various functions were the result of overall activities.In 1870, German young doctors Fritz and Hizich used electricity to stimulate dogscerebral cortexArea, finding a cortexRegional managementThe movement of the opposite side of the body, so first put forward“Sports area”The concept of.Later, it was found that there was a more detailed division of labor in the cortical motor area, which was responsible for specific parts of the upper limbs, lower limbs and trunk.In addition, there are other functional areas.
Stimulatory method
Announce
edit
century,CanadaDoctor Penfield uses micro electricityStimulatory method, comprehensively and in detailcerebral cortexThe division of labor ofSensory functionThe projection on the cerebral cortex is inverted, and some organs with fine and dexterous movements and senses (such as hands, lips, tongue, etc.) have a larger projection area on the cerebral cortex than those with simple and dull movements and senses (such as the trunk).
Then, French doctor Broca found that patients with right hemiplegia were often accompanied byaphasiaPostmortem autopsy revealed that the patient was leftCerebral hemispherefrontal lobePathological changes;Patients with left hemiplegia are not accompanied byaphasiaTherefore, it is first proposed that“Language center”And called the left hemisphere“Dominant hemisphere”。For right-handed people (about 90%), all relevant language activities, such as reading and writing, understanding and naming, calculation and reasoning, are located in the left hemisphere.
So, does the right hemisphere (non dominant hemisphere) tend to degenerate?This is a very interesting question.From left to rightCerebral hemispheresFrom the perspective of mutual connection, first of all, they use a bunch of powerfulnerve fiber(about 200 million nerves)——corpus callosumConnect and exchange information between the two hemispheres.This is both a division of labor and a whole.In the 1970s, American scientist Sperry and his colleagues didSchizencephalonSurgery - amputationCallose, to treat some uncontrollable drugsEpilepsyAnd did a lot of very finePsychological experimentThe results showed that the two hemispheres of the brain had independent functions.They are: LeftCerebral hemisphereHave the ability of language, reading, writing, logic, reasoning and calculation;The right hemisphere has figuresspace structureThe ability to conceive, enjoy music, and form nonverbal concepts.The thinking activity of the left hemisphere is a unique human function, which can be explainedHuman Brain EvolutionThe development trend of lateralization also indicates that human brain has great potential
Central nervous system
Announce
edit
braincentral nervous systemThe highest part of the brain is also the main part of the brain.It is divided into the left and right cerebral hemispheres, which are connected by the corpus callosum composed of nerve fibers.Covered inCerebral hemisphereThe gray matter on the surface is calledCerebral cortex。It contains many pyramidal nerve cells and other types of nerve cells and nerve fibers.The deep surface of cortex is medulla, which containsNerve fiber bundleAnd nuclear clusters.staymedullaThe ventricles in the brain areLateral ventricle, containing transparentcerebrospinal fluid。The gray matter nuclei buried in the medulla areBasal ganglia。On the surface of the cerebral hemisphere, there are many fissures of different depths (convex is gyrus, concave is groove).The main ones areCentral sulcusLateral cerebral fissure, parietooccipital fissure.The human cerebral hemisphere is highly developed.Adult cerebral cortexSurface areaIt is about 1/4 square meter and contains about 14 billion neuron cell bodies. There are extensive and complex connections between themAdvanced nervous activityThe center of.CorticalInternal capsuleConnect with the subordinate center.The outside of the brain containsconnective tissueThe capsule and cerebrospinal fluid of the brain are filled in the cavities, chambers and tubes of the brain, which have protective and nutritional effects.The blood supply to the brain comes fromvertebral arteryandInternal carotid arteryget.
The human brain has more than 100 billion nerve cells, which can record about 86 million pieces of information in life every day.
Human Brain Development
Announce
edit
The brain occupies the majority of the cranial cavity.It accounts for about 2% of the adult's weight, i.e. 1.2~1.6 kg.The brain weight of men is slightly larger than that of women, and has nothing to do with body weight.Brain contains about 14 billionnerve cellAboutBrain cellOne tenth, the remaining 90% is calledGlial cell。Glial cells provide nutrition for nerve cells and formmyelin sheathpromoteconduction velocity , and other functions.It is often said that "the effective use of the human brain only accounts for about one tenth", which may be a misunderstanding from the era when the function of glial cells was not fully understood. It is believed that only nerve cells are working in the brain, which means that there is no credible theory about 10% of the development of the human brain.
Brain volume
Announce
edit
Guinness World RecordsOne Englishman who remembers most of the cards in Zhongji is able to remember 54 pairs of washed cards at a glancepoker(2808 cards in total!).
In the 1920s, Alexander Aitken could remember pidecimal pointThe last 1000 digits, but this record was recorded by an IndianMaster of MemoryIf broken, he can remember 31811 digits after the decimal point;This record was later broken by a Japanese memory master who could remember 42905 digits after the decimal point!
You may not be able to imitate such amazing skills, but you can use the same methods as these memory masters to improve and enhance your intelligence and memory.It doesn't matter how smart you are or how highly educated you have been. There are many tricks and techniques that can help you make the most of your brain cells
brain activity
Announce
edit
If the activity of the brain can be converted into electrical energy, it is equivalent to the power of a 20 watt bulb.
According to some measurements made by neuroscientists, the neural cell circuit of the human brain is more than 1400 times more complex than the telephone network in the world today.
5 kinds of human bodysense organOnly 1% of the constantly received information is processed by the brain, and the remaining 99% are screened out.
The fastest among brain nerve cellsNerve impulseThe conduction speed is more than 400 km/h
The brain is surrounded by a thin film containing veins and arteries, which is full ofsensory nerve。But the brain itself does not feel, even if the brain is divided into two, people will not feel pain.
The average human brain is 2% of the total body weight, but it needs 25% of the oxygen used by the whole body, compared with 12% for the kidney and 7% for the heart.Neural signalIn nerves orMuscle fibreThe transmission speed in can be as high as 200 miles per hour.
There are 45 miles of nerves in the body.
The number of human brain cells exceeds that of the worldTotal populationMore than twice, it can process 86 million pieces of information every day, and its memory stores more information than any electroniccomputer。
Related technologies
Announce
edit
Current vshuman brainThe related high and new technologies areBrain chip。first caseHuman brain chipIn 1950, Husse Delgado tried to perform this operation on humans: change people's emotions by slightly stimulating a part of the human brain, and even control a person's arm or leg.In the end, the experiment was terminated because it was contrary to ethics.But since then, the method of stimulating the brain with electric current has been proved to be able to treat certain diseases.For example, cochlear implantation, which began more than 30 years ago, can help some deaf people recover part of their hearing.The research in this field has become a hot spot again.Some scientists even imagine that through some devices, people can rely on thinking to control the operation of machines.Some paralyzed patients have successfully achieved this by using electrodes implanted in the brain.
Previous similar studies were limited toTraditional computerUpper developmentNeural network modelOr onSupercomputerThe new research idea is: R&D in the sizeprocessing speed And energy consumption can be comparable to the real brain circuit.Kirkmo Indiverry, a member of the research team, said: "Our goal is to directly simulate biology on the microchipneuronandSynapse"
The main challenge to achieve this is to configureArtificial neuronA network that allows it to perform specific tasks.Now the research team has successfully conquered this "blockhouse". They have developed a device called "neural chips", which can execute complexSensorimotorTask, and with the help of this device, demonstrated a context dependentDecision making abilityThis is a typical feature of cognitive testing.
The research team put the neural morphologyneuronWith the use of neural processing module - equivalent to the so-called“Finite automaton”The network.Finite automata is aDescription logicProcess and ComputerprogramOfMathematical concept。Behavior can be expressed as a finite automaton, which is automatically transferred to the neuromorphic hardware.Indiverri said:“network connectionsThe pattern is very similar to the structure found in the brain. "
Because the neuromorphochip canreal-time processingRelevant experts believe that this technology is expected to be practical, so as to allow robots in complex environmentsRemote controlTo realize automatic operation.
The adoption of this technology is also expected to enable computers to continue to operate when parts are damaged in the future. Just like human brain, millions of brain cells are lost every day, but its overallThinking abilityBut it still continues to operate normally.
The European Union, the United States and Switzerland are currently working intensively to develop neural network computers that simulate brain processing information, hoping to replicate artificial intelligence systems by simulating biological neurons.This new type of computer“Brain chip”It is quite different from the "brain chip" of traditional computers.It can use neural calculation method similar to human brain,Low energy consumptionandFault toleranceStrong is its greatest advantage, compared with traditionaldigital computer, its intelligence will be strongerCognitive learning, Auto Organize, Alignfuzzy information And other aspects will also make a big step forward.
However, some people expressed concern: will robots equipped with such chips surpass humans in intelligence in the future, or even pose a threat to humans?
Many scientists believe that such concerns are totally unnecessary.As far as intelligence is concerned, the intelligence quotient of robots is equivalent to that of 4-year-old children, and the "common sense" of robots is far worse than that of normal adults.Robert Sloan, an American scientist, said recently: "We are far from being able to answer with the ability of 8-year-old childrenComplex problemsA common sense AI program is still far away. "Japanese scientist Masao Hirose also believes that even if robots have common sense and can carry outSelf replicationIt is also impossible to pose a threat to human beings.It is worth mentioning that Chinese scientistsZhou HaizhongIn the article "On Robots" published in 1990, it was pointed out that robots are not omnipotent;It is in the working intensityOperation speedandmemory function It can surpass human beings in terms of consciousness and reasoning, but it is impossible to surpass human beings in terms of consciousness and reasoning.In addition, robots will become more and more "smart", but they can only act in accordance with the principles and programs formulated to serve and benefit mankind.[1]
2023，The team from Northwestern University School of Medicine reported the results of a phase I human clinical trial. They used a new type of skull implant ultrasound device to open the blood-brain barrier and repeatedly infiltrate chemotherapy drugs into large key areas of the human brain to enhance the therapeutic effect.[2]
