Related topics: brain
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
Wikipedia.
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News tagged with brain tissue
Research sheds new light on epilepsy
Nov 30, 2009 |
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Pioneering research using human brain tissue removed from people suffering from epilepsy has opened the door to new treatments for the disease.
Naked mole rats may hold clues to surviving stroke
Nov 30, 2009 |
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Blind, nearly hairless, and looking something like toothy, plump, pink fingers, naked mole rats may rank among nature's most maligned creatures, but their unusual physiology endears them to scientists.
Docs say formerly conjoined twins recovering well
Nov 25, 2009 |
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(AP) -- Formerly conjoined twin sisters Trishna and Krishna are enjoying a favorite DVD and trying new foods as they continue their recovery from marathon separation surgery, doctors said.
New discovery about the formation of new brain cells
Nov 23, 2009 |
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The generation of new nerve cells in the brain is regulated by a peptide known as C3a, which directly affects the stem cells' maturation into nerve cells and is also important for the migration of new nerve cells through ...
Formerly conjoined twins in stable condition
Nov 17, 2009 |
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(AP) -- A team of 16 surgeons and nurses successfully concluded 25 hours of delicate surgery Tuesday to separate twin Bangladeshi girls who had been joined at their heads, sharing blood vessels and brain ...
On your last nerve: Researchers advance understanding of stem cells
Nov 17, 2009 |
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Researchers from North Carolina State University have identified a gene that tells embryonic stem cells in the brain when to stop producing nerve cells called neurons. The research is a significant advance ...
Twins joined at head successfully separated (Update 2)
Nov 17, 2009 |
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(AP) -- A team of 16 surgeons and nurses successfully concluded 25 hours of delicate surgery Tuesday to separate twin Bangladeshi girls who had been joined at their heads, sharing blood vessels and brain ...
Protein changes in heart strengthen link between Alzheimer's disease and chronic heart failure
Nov 16, 2009 |
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A team of U.S., Canadian and Italian scientists led by researchers at Johns Hopkins report evidence from studies in animals and humans supporting a link between Alzheimer's disease and chronic heart failure, two of the 10 ...
Study identifies new way to biopsy brain tumors in real time
Medicine & Health / Neuroscience
Nov 11, 2009 |
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A new miniature, hand-held microscope may allow more precise removal of brain tumors and an easier recognition of tumor locations during surgery.
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?
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. ...
Hybrid molecules show promise for exploring, treating Alzheimer's
Nov 04, 2009 |
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One of the many mysteries of Alzheimer's disease is how protein-like snippets called amyloid-beta peptides, which clump together to form plaques in the brain, may cause cell death, leading to the disease's devastating symptoms ...
Unlocking mysteries of the brain with PET
Oct 30, 2009 |
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Inflammatory response of brain cells—as indicated by a molecular imaging technique—could tell researchers more about why certain neurologic disorders, such as migraine headaches and psychosis in schizophrenic patients, occur ...
Member of NFL Hall of Fame diagnosed with degenerative brain disease
Oct 28, 2009 |
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The Center for the Study of Traumatic Encephalopathy (CSTE) at Boston University School of Medicine (BUSM) announced today that a recently deceased member of the NFL Hall of Fame suffered from the degenerative brain disease ...
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 ...
