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
Epilepsy Patients Are Given New Hope With Brain Implant
Medicine & Health / Neuroscience
Dec 09, 2009 |
5 / 5 (4) |
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(PhysOrg.com) -- A startup company, Neuropace in Mountain View Ca., has developed a device that offers new hope for epilepsy patients. The device is designed to neutralize the abnormal electrical activity ...
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.
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?
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 ...
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.
Study surprise yields new target for assessing genes linked to autism
Oct 21, 2009 |
4.6 / 5 (5) |
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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 ...
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 ...
Scientists discover area of brain that makes a 'people person'
Medicine & Health / Neuroscience
May 20, 2009 |
4.2 / 5 (12) |
6
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 ...
Flow of potassium into cells implicated in schizophrenia
May 06, 2009 |
5 / 5 (8) |
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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 ...
In the Middle of Brain Surgery, Patients Wake Up and Begin Talking
Sep 11, 2009 |
4.6 / 5 (11) |
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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.
Crossing the line: how aggressive cells invade the brain (w/ Video)
Nov 05, 2009 |
4.6 / 5 (5) |
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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. ...
New evidence ties gene to Alzheimer's
Medicine & Health / Neuroscience
May 06, 2009 |
4.8 / 5 (4) |
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Of dozens of candidates potentially involved in increasing a person's risk for the most common type of Alzheimer's disease that affects more than 5 million Americans over the age of 65, one gene that keeps grabbing Johns ...
Twins joined at head successfully separated (Update 2)
Nov 17, 2009 |
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0
(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 |
5 / 5 (1) |
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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 ...
Researcher regenerates brain tissue in traumatic injuries
Sep 02, 2009 |
4 / 5 (1) |
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An injectable biomaterial gel may help brain tissue grow at the site of a traumatic brain injury, according to findings by a Clemson University bioengineer.
