Related topics: brain · genes · brain cells · neurons · neuroscientists

Does the human brain resemble the Universe?

An astrophysicist at the University of Bologna and a neurosurgeon at the University of Verona compared the network of neuronal cells in the human brain with the cosmic network of galaxies... and surprising similarities emerged

How to read a jellyfish's mind

The human brain has 100 billion neurons, making 100 trillion connections. Understanding the precise circuits of brain cells that orchestrate all of our day-to-day behaviors—such as moving our limbs, responding to fear and ...

Smarter brains are blood-thirsty brains

A University of Adelaide-led project has overturned the theory that the evolution of human intelligence was simply related to the size of the brain—but rather linked more closely to the supply of blood to the brain.

Cro Magnon skull shows that our brains have shrunk

(PhysOrg.com) -- A new replica of an early modern human brain has provided further evidence for the theory that the human brain has been shrinking. The skull belonged to an elderly Cro Magnon man, whose skeleton is called ...

Brain waves detected in mini-brains grown in a dish

Scientists have created miniature brains from stem cells that developed functional neural networks. Despite being a million times smaller than human brains, these lab-grown brains are the first observed to produce brain waves ...

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Human brain

The 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.

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