Thursday, September 29, 2022

What Is The Human Brain Made Of

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When You Learn You Change The Structure Of Your Brain

Is Your Brain Really Made of FAT?

Riding a bike seems impossible at first, but soon you master it. How? As you practise, your brain sends bike riding messages along pathways of neurons again and again, forming new connections. In fact, the structure of your brain changes every time you learn, as well as whenever you have a new thought or memory. Now thats clever!

What White Matter Consists Of

White matter consists of millions of bundles of axons, or nerve fibers. Axons are portions of the nerve cell that carries nerve impulses away from the cell body.

Axons are long slender-like structures that extend away from the cell body. The axons that make up the white matter are covered in a white substance called myelin sheath.

Myelin sheath is a sleeve of fatty tissue that insulates the axons and gives white matter its white appearance. Myelin works to insulate the axons of the nerve cells to ensure a higher speed of transmission of electrical signals.

Myelinated nerves can carry electrical impulses up to 100 times faster than non-myelinated nerves so if they were to be damaged, this can impact on sensory, motor, and cognitive functions.

Myelin sheath is made by the types of non-neuronal cells which are also present in the white matter, called oligodendrocytes. These types of cells are known as a glial cell, which are cells that provide support or protection to the neurons. Oligodendrocytes form the myelin and wrap this around the axons up to 150 times.

All the layers of myelin is tightly compressed around the axon to ensure it is protected. On the axon, there are gaps in the myelin sheath called nodes of Ranvier.

These unmyelinated gaps cause the impulses traveling along the length of the axon to leap from node to node. When it does this, the signal increases in velocity so it can reach its destination quicker than traveling down the axon without nodes.

How Much Does A Human Brain Weigh

The human brain weighs about 3 lbs. and makes up about 2% of a human’s body weight. On average, male brains are about 10% larger than female brains, according to Northwestern Medicine in Illinois. The average male has a brain volume of nearly 78 cubic inches , while the average female brain has a volume of 69 cubic inches . The cerebrum, which is the main part of the brain located in the front area of the skull, makes up 85% of the brain’s weight.

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What’s The Difference Between The Left Brain And Right Brain

The human brain is divided into two hemispheres, the left and right, connected by a bundle of nerve fibers called the corpus callosum. The hemispheres are strongly, though not entirely, symmetrical. Generally, the left brain controls the muscles on the right side of the body, and the right brain controls the left side. One hemisphere may be slightly dominant, as with left- or right-handedness.

Related: What’s the difference between the right brain and the left brain?

The popular notions about “left brain” and “right brain” qualities are generalizations that are not well supported by evidence. However, there are some important differences between these areas. The left brain contains regions that are involved in language production and comprehension and is also associated with mathematical calculation and fact retrieval, Holland said. The right brain plays a role in visual and auditory processing, spatial skills and artistic ability more instinctive or creative things, Holland said though these functions involve both hemispheres. “Everyone uses both halves all the time,” he said.

Right Brain Left Brain

Does the Brain

The cerebrum is divided into two halves: the right and left hemispheres They are joined by a bundle of fibers called the corpus callosum that transmits messages from one side to the other. Each hemisphere controls the opposite side of the body. If a stroke occurs on the right side of the brain, your left arm or leg may be weak or paralyzed.

Not all functions of the hemispheres are shared. In general, the left hemisphere controls speech, comprehension, arithmetic, and writing. The right hemisphere controls creativity, spatial ability, artistic, and musical skills. The left hemisphere is dominant in hand use and language in about 92% of people.

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Introduction: The Human Brain

A false-colour Magnetic Resonance Image of a mid-sagittal section through the head of a normal 42 year-old woman, showing structures of the brain, spine and facial tissues

The brain is the most complex organ in the human body. It produces our every thought, action, memory, feeling and experience of the world. This jelly-like mass of tissue, weighing in at around 1.4 kilograms, contains a staggering one hundred billion nerve cells, or neurons.

The complexity of the connectivity between these cells is mind-boggling. Each neuron can make contact with thousands or even tens of thousands of others, via tiny structures called synapses. Our brains form a million new connections for every second of our lives. The pattern and strength of the connections is constantly changing and no two brains are alike.

It is in these changing connections that memories are stored, habits learned and personalities shaped, by reinforcing certain patterns of brain activity, and losing others.

A Sorting Station: The Thalamus Mediates Sensory Data And Relays Signals To The Conscious Brain

The diencephalon is a region of the forebrain, connected to both the midbrain and the cerebrum. The thalamus forms most of the diencephalon. It consists of two symmetrical egg-shaped masses, with neurons that radiate out through the cerebral cortex. Sensory data floods into the thalamus from the brain stem, along with emotional, visceral, and other information from different areas of the brain. The thalamus relays these messages to the appropriate areas of the cerebral cortex. It determines which signals require conscious awareness, and which should be available for learning and memory.

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The Brain Stem Relays Signals Between The Brain And Spinal Cord And Manages Basic Involuntary Functions

The brain stem connects the spinal cord to the higher-thinking centers of the brain. It consists of three structures: the medulla oblongata, the pons, and the midbrain. The medulla oblongata is continuous with the spinal cord and connects to the pons above. Both the medulla and the pons are considered part of the hindbrain. The midbrain, or mesencephalon, connects the pons to the diencephalon and forebrain. Besides relaying sensory and motor signals, the structures of the brain stem direct involuntary functions. The pons helps control breathing rhythms. The medulla handles respiration, digestion, and circulation, and reflexes such as swallowing, coughing, and sneezing. The midbrain contributes to motor control, vision, and hearing, as well as vision- and hearing-related reflexes.

The Brain Elevated Genes Comparing Brain To Other Organs And Tissue Types

The Human Brain: How We Decide

Out of the 16507 genes detected above cut off in the human brain, 2709 genes have an elevated expression in the brain compared to other tissue types. Tissue specificity category defines protein coding genes with elevated expression levels in the brain, while the tissue distribution category indicate transcript detection above cut off . The fraction of all protein coding genes in each category is shown Figure 2 and Table 1.

Figure 2. The distribution of all genes across the five categories based on transcript abundance in brain as well as in all other tissues. The distribution of all genes across the six categories, based on transcript detection in brain as well as in all other tissues.

Brain expression is determined by expression above cut off .

  • Detected in single: Detected only in brain
  • Detected in some: Detected in brain and at least one more tissue, but less than one-third of tissues
  • Detected in many: Detected in at least a third but not all tissues including brain

Elevated expression in brain compared to other tissue types is divided into three different categories

  • Tissue enriched: At least four-fold higher mRNA level in brain compared to any other tissues
  • Group enriched: At least four-fold higher average mRNA level in a group of 2-5 tissues compared to any other tissue .
  • Tissue enhanced: At least four-fold higher mRNA level in brain compared to the average level in all other tissues .

Distribution in the 36 tissues Detected in single

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The Remarkable Yet Not Extraordinary Human Brain As A Scaled

  • Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, 21941-902, Rio de Janeiro, Brazil and Instituto Nacional de Neurociência Translacional, Instituto Nacional de Ciência e Tecnologia/Ministério de Ciência e Tecnologia, 04023-900, Sao Paulo, Brazil
  • See allHide authors and affiliations

    • For correspondence:
  • Edited by Francisco J. Ayala, University of California, Irvine, CA, and approved April 12, 2012

    • How Does The Brain Work

      The brain sends and receives chemical and electrical signals throughout the body. Different signals control different processes, and your brain interprets each. Some make you feel tired, for example, while others make you feel pain.

      Some messages are kept within the brain, while others are relayed through the spine and across the bodys vast network of nerves to distant extremities. To do this, the central nervous system relies on billions of neurons .

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      Introduction To What Human Beings Are Comprised Of

      In this article we explain the composition of the human body and its various subtle bodies. Modern science has gone in some depth into understanding the physical body. Yet its understanding of the other aspects of human existence is still very limited. For example the understanding of the human psyche and intellect is still more or less limited to their physical aspects. On the other hand, spiritual science has studied the entire human existence in great detail.

      How Do Brains Change With Age

      How Does the Human Brain Remember Things?

      As we age, parts of our brain begin to shrink naturally and we begin to gradually lose neurons. The frontal lobe and the hippocampus two key brain regions in regulating cognitive processes, including memory formation and recall start shrinking when we hit 60 or 70.

      This means that we could naturally begin to find learning new things, or performing several tasks at the same time, more challenging than before.

      There is some good news, as well, however. Till not too long ago, scientists used to believe that once we started to lose neurons, that would be it we would be unable to create new brain cells and had to resign ourselves to that.

      However, it turns out that this isnt true. Researcher Sandrine Thuret, from Kings College London in the United Kingdom, has explained that the hippocampus is a crucial part in the adult brain in terms of generating new cells.

      The process in which new nerve cells are created in the adult brain is called neurogenesis, and, according to Thuret, estimates suggest that an average adult human will produce 700 new neurons per day in the hippocampus.

      This, she suggests, means that when we reach middle age, we will have replaced all the neurons that we had in this brain region in the beginning of our lives with ones that we produced during adulthood.

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      Is Perception A Controlled Hallucination

      A great mystery of the human brain is linked with consciousness and our perception of reality. The workings of consciousness have fascinated scientists and philosophers alike, and though we are slowly inching closer to an understanding of this phenomenon, much more still remains to be learned.

      Anil Seth, a professor of cognitive and computational neuroscience from the University of Sussex in the U.K., who specializes in the study of consciousness, has suggested that this intriguing process is based on a sort of controlled hallucination, which our brains generate to make sense of the world.

      Perception figuring out whats there has to be a process of informed guesswork in which the brain combines these sensory signals with its prior expectations of beliefs about the way the world is to form the best guess of what caused those signals.

      Prof. Anil Seth

      According to him, in delivering perceptions of things to our consciousness, our brains often make what you might call informed guesses, based on how it expects things to be.

      This explains the uncanny effect of many optical illusions, including the now-notorious blue and black, or white and gold dress, when, depending on how we think the light in the picture is, we may see a different color combination.

      Below, you can watch Prof. Seths 2017 TED talk. He explains how our brains make sense of the world around us and within us.

      Does The Brain Stay Alive After A Person Dies

      April 2019 marked a milestone for both the initiative and neuroscience research at large: BRAIN Initiative researcher Nenad Sestan, of the Yale School of Medicine, published a report in the journal Nature, revealing that his research team had restored circulation and some cellular functions to pig brains four hours after the animals’ deaths, Live Science previously reported. The results challenged the prevailing view that brain cells are suddenly and irreversibly damaged shortly after the heart stops beating. The researchers did not observe any signs of consciousness in the brains, nor were they trying to on the contrary, the researchers injected pig brains with chemicals that mimicked blood flow and also blocked neurons from firing. The researchers emphasized that they did not bring the pig brains back to life. They did, however, restore some of their cellular activity.

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      Cranial Chemicals And Their Applications

      Almost all these chemicals are also known as neurotransmitters, which means they help in passing and modulating signals between neurons and other cells. A group of about 10 molecules, and more than 50 neuroactive proteins form the neurotransmitters. Several singular ions as well as few fatty acids can also be classified under this category. The chemicals themselves cannot determine their effect, which is controlled by the receptor they go to.

      Normally, neurotransmitter molecules are enclosed in vesicles, and a synaptic depolarization results in the opening of calcium ion channels, which releases them. This process is known as exocytosis. When these transmitters are released through exocytosis, they disseminate across the synaptic divide and stick to receptors. Re-uptake is the process by which these transmitters are taken away from the receptors, which clears the channel rendering no neuron stimulated. Neuroactive drugs that affect the brain are known to use the removal mechanisms to their advantage. The dopamine system, noradrenaline system, serotonin system, and cholinergic system are the major neurotransmitter systems in the brain.

      Your Brain Generates Enough Electricity To Power A Lightbulb

      What is the brain made out of ?

      Your brain contains about 100 billion microscopic cells called neurons. There are so many, it would take you over 3,000 years to count them all! Whenever you dream, laugh, think, see or move, its because minute chemical and electrical signals are racing between these neurons along billions of tiny neuron pathways. Incredibly, the activity in your brain never stops. Countless messages zip around inside it every second just like a supercharged pinball machine. Your neurons create and send more messages than all the phones in the entire world. And while a single neuron generates only a very small amount of electricity, all your neurons together can produce enough energy to power a low-wattage light bulb. Imagine that!

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      What Happens When You Exercise Your Brain

      Exercising your brain using cognitive training tools, which are also called brain training games or brain exercises, may help improve your cognitive functioning.

      Some studies have found that brain exercises improve memory, executive functions, and processing speeds, while others have shown little to no effect.

      The impact of brain exercises may have something to do with age. Some studies have shown an improvement in cognitive abilities in young people and older adults. Nouchi R, et al. . Brain training game boosts executive functions, working memory and processing speed in the young adults: A randomized controlled trial. DOI: 10.1371/journal.pone.0055518

      Brain exercises may also be beneficial in slowing age-related changes in the brain and those associated with neurological conditions, such as Alzheimers disease and dementia.

      A study published in 2017 showed that a brain-training intervention known as speed-of-processing training significantly reduced dementia risk. Edwards JD, et al. . Speed of processing training results in lower risk of dementia. DOI: 10.1016/j.trci.2017.09.002

      If youre looking to exercise your brain, you dont necessarily need to resort to brain training games and apps.

      Your brain is made up of different parts that all work together. Lets take a look at the different parts of the brain and what they do.

      What Are The Different Tasks Handled By The Different Areas Of The Cortex

      • Checks movements as they happen

      How does the cerebellum coordinate posture, balance and movement?

      • The control centers of the middle and base of the cerebellum control these actions by responding to information coming into the brain from the ears , the eyes and the stretch sensors in muscles and joints.
      • These messages tell the brain about the position and movements of various body parts like head, neck and trunk.
      • The cerebellum sorts through the messages and sends out instructions to muscles, again mainly in the head, neck and trunk.
      • The muscles work in a precise way to keep the body moving smoothly in a well-balanced manner, so we do not stumble or fall.

      The cerebellum also checks movements as they happen, and fine-tunes them with small adjustments. If a drastic problem takes place, the cerebellum sends signals back to the cortex, in order to make us think to deal with the problem.

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