Related topics: brain , stem cells , brain cells , stroke , nerve cells
Human brain
hideThe human brain is the center of the human nervous system and is a highly complex organ. Enclosed in the cranium, it has the same general structure as the brains of other mammals, but is over three times as large as the brain of a mammal with an equivalent body size. Most of the expansion comes from the cerebral cortex, a convoluted layer of neural tissue that covers the surface of the forebrain. Especially expanded are the frontal lobes, which are involved in executive functions such as self-control, planning, reasoning, and abstract thought. The portion of the brain devoted to vision is also greatly enlarged in humans.
Brain evolution, from the earliest shrewlike mammals through primates to hominids, is marked by a steady increase in encephalization, or the ratio of brain to body size. The human brain has been estimated to contain 50–100 billion (1011) neurons[citation needed], of which about 10 billion (1010) are cortical pyramidal cells.[citation needed] These cells pass signals to each other via approximately 100 trillion (1014)[citation needed] synaptic connections.
In spite of the fact that it is protected by the thick bones of the skull, suspended in cerebrospinal fluid, and isolated from the bloodstream by the blood-brain barrier, the delicate nature of the human brain makes it susceptible to many types of damage and disease. The most common forms of physical damage are closed head injuries such as a blow to the head, a stroke, or poisoning by a wide variety of chemicals that can act as neurotoxins. Infection of the brain is rare because of the barriers that protect it, but is very serious when it occurs. More common are genetically based diseases[citation needed], such as Parkinson's disease, multiple sclerosis, and many others. A number of psychiatric conditions, such as schizophrenia and depression, are widely thought to be caused at least partially by brain dysfunctions, although the nature of such brain anomalies is not well understood.
For more information about Human brain, read the full article at
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News tagged with brain tissue
Why can't chimps speak? Study links evolution of single gene to human capacity for language
Nov 11, 2009 |
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(PhysOrg.com) -- If humans are genetically related to chimps, why did our brains develop the innate ability for language and speech while theirs did not?
In the Middle of Brain Surgery, Patients Wake Up and Begin Talking
Sep 11, 2009 |
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Kim Delvaux was undergoing surgery to remove a brain tumor when doctors at Loyola University Hospital woke her up. Dr. Vikram Prabhu talked to her about her favorite topics -- NASCAR and her kids.
Scientists discover area of brain that makes a 'people person'
Medicine & Health / Neuroscience
May 20, 2009 |
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Cambridge University researchers have discovered that whether someone is a 'people-person' may depend on the structure of their brain: the greater the concentration of brain tissue in certain parts of the ...
A step toward better brain implants using conducting polymer nanotubes
Nanotechnology / Nanomaterials
Sep 29, 2009 |
5 / 5 (9) |
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ANN ARBOR, Mich.---Brain implants that can more clearly record signals from surrounding neurons in rats have been created at the University of Michigan. The findings could eventually lead to more effective ...
Nanoparticles cross blood-brain barrier to enable 'brain tumor painting'
Nanotechnology / Bio & Medicine
Aug 03, 2009 |
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Brain cancer is among the deadliest of cancers. It's also one of the hardest to treat. Imaging results are often imprecise because brain cancers are extremely invasive. Surgeons must saw through the skull ...
How blast waves cause human brain injury even without direct head impacts?
Aug 26, 2009 |
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New research on the effects of blast waves could lead to an enhanced understanding of head injuries and improved military helmet design.
Flow of potassium into cells implicated in schizophrenia
May 06, 2009 |
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A study on schizophrenia has implicated machinery that maintains the flow of potassium in cells and revealed a potential molecular target for new treatments. Expression of a previously unknown form of a key ...
Inexpensive hypertension drug could be multiple sclerosis treatment
Aug 17, 2009 |
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Turning serendipity into science, researchers at the Stanford University School of Medicine have found a link, in mice and in human brain tissue, between high blood pressure and multiple sclerosis. Their findings suggest ...
Nicotine may have more profound impact than previously thought
Apr 03, 2009 |
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Nicotine isn't just addictive. It may also interfere with dozens of cellular interactions in the body, new Brown University research suggests.
Neurologists Investigate Possible New Underlying Cause of MS
Medicine & Health / Neuroscience
Oct 14, 2009 |
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(PhysOrg.com) -- Neurologists at the University at Buffalo are beginning a research study that could overturn the prevailing wisdom on the cause of multiple sclerosis (MS). The researchers will test the possibility that ...
Stunning Finding: Compounds Protect Against Cerebral Palsy
Feb 25, 2009 |
5 / 5 (5) |
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(PhysOrg.com) -- Two compounds developed by Northwestern University chemists have been shown to be effective in pre-clinical trials in protecting against cerebral palsy, a condition caused by neurodegeneration that affects ...
Tracking down the causes of multiple sclerosis
Jun 10, 2009 |
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Over 100,000 people suffer from multiple sclerosis in Germany alone. Despite intensive research, the factors that trigger the disease and influence its progress remain unclear. Scientists from the Max Planck ...
Protein inhibitor helps rid brain of toxic tau protein
Medicine & Health / Neuroscience
Sep 29, 2009 |
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Inhibiting the protein Hsp70 rapidly reduces brain levels of tau, a protein associated with Alzheimer's disease when it builds up abnormally inside nerve cells affecting memory, neuroscientists at the University ...
Study surprise yields new target for assessing genes linked to autism
Oct 21, 2009 |
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Researchers at Duke University Medical Center have uncovered a new genetic signature that correlates strongly with autism and which doesn't involve changes to the DNA sequence itself. Rather, the changes are in the way the ...
Crossing the line: how aggressive cells invade the brain (w/ Video)
Nov 05, 2009 |
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In diseases such as multiple sclerosis, cells of the immune system infiltrate the brain tissue, where they cause immense damage. For many years, it was an enigma as to how these cells can escape from the bloodstream. ...
