A brain is an organ that serves as the center of the nervous system in all vertebrate and most invertebrate animals. It is located in the head, usually close to the sensory organs for senses such as vision. It is the most complex organ in a vertebrate's body. In a human, the cerebral cortex contains approximately 14–16 billion neurons, and the estimated number of neurons in the cerebellum is 55–70 billion. Each neuron is connected by synapses to several thousand other neurons. These neurons typically communicate with one another by means of long fibers called axons, which carry trains of signal pulses called action potentials to distant parts of the brain or body targeting specific recipient cells.
Physiologically, brains exert centralized control over a body's other organs. They act on the rest of the body both by generating patterns of muscle activity and by driving the secretion of chemicals called hormones. This centralized control allows rapid and coordinated responses to changes in the environment. Some basic types of responsiveness such as reflexes can be mediated by the spinal cord or peripheral ganglia, but sophisticated purposeful control of behavior based on complex sensory input requires the information integrating capabilities of a centralized brain.
The operations of individual brain cells are now understood in considerable detail but the way they cooperate in ensembles of millions is yet to be solved. Recent models in modern neuroscience treat the brain as a biological computer, very different in mechanism from an electronic computer, but similar in the sense that it acquires information from the surrounding world, stores it, and processes it in a variety of ways.
This article compares the properties of brains across the entire range of animal species, with the greatest attention to vertebrates. It deals with the human brain insofar as it shares the properties of other brains. The ways in which the human brain differs from other brains are covered in the human brain article. Several topics that might be covered here are instead covered there because much more can be said about them in a human context. The most important is brain disease and the effects of brain damage, that are covered in the human brain article.
Is fatal degenerative brain disease inevitable? If we could transplant ourselves into clones every 20 years or something like that, how long would we be able to live before degenerative brain disease, or something like that, killed us?
I'm attaching this here (hope that's ok) because the brain teaser forum is unmoderated. Anyone who's interested, the brainteaser this relates to is "cursive letters."
I have been thinking for the past week on how the mind works, and classical physics theory has plenty of holes in it.
The most convincing aspect of my new theory is with how the brain and memory work. When you wish to remember something, could the brain and its neurons be sending an advance...
Here is another brain Teaser...
in 2D not 3D assume crossing lines disrupts the electric field,
3 houses need to be hooked up to electrical, telephone and gas. Is it possible to hook every house up to every building without crossing lines?
I know this is impossible but can anyone...
Many physical constant can be expressed in terms of Energy, Time [T] and Distance [L].
Now some basic qestions for a brain storming session.
1. if acceleration is L/T^2 then what name would you give the next term L/T^3 ?
2. if the speed of light is the maximum speed is there also a...
Jack and John are twins, (They're each the other one's twin, we'll say they're identical.) Jack was born in May. John was born in February. [hmm, usually the next part is: When Jack was 20 John was 20 too, (sounds like 22, hence the riddle) but it doesn't work when i spell it... awell...] When...
Human brain is an observer , and the problem of this idea is observing himself
the brain will observe an observer observe an observer observe an observer ... to infinity.
the real problem appears to people who work in computional simulation of brain ( infinite loop )
can this cycle have any...
This was in a maths textbook.
An arrow approaches its mark, (where its supposed to hit) but as it approaches closer and closer, it will approach half the distance it was at some time ago away from the target, and so on and so on and so on..
So I am asking: Why does the arrow ever reach...
I just played thay dark room game that was posted in brain teasers, pretty fun. It reminded me of this game i played a few months ago called MOTAS. I think some of you will really enjoy it, i also think some of you might really hate it and feel stupid because you won't be able to do it...
ok...
note: Earth's pull of gravity starts 2.7 billion light years away.<Got this info from somewhere else>(may not be true, u are free to use u'r own)
A comet which is floating freely in space, suddenly, got attracted by Earth's gravity and started accelerating at 10m/s-2 towards...
Mr. Smith and his wife Mrs. Smith invited four other couples to a party.
When everyone arrived, some shook hands with some of the others. Ofcourse, no one shook hands with his/her spouse or him/herself and none shook hands with the same person twice.
Afterwards Mr. Smith asked everyone how...
Three related brain teasers:(I did not see them posted before)
There is a mint, let's say the Denver mint. In the mint there are 100 penny making machines. In the problems below there is something wrong with one of the machines. You may produce as many coins as you would like from any of...
The Origin of Mind: Evolution of Brain, Cognition, and General Intelligence, 2005
Hello,
I liked the book The Origin of Mind: Evolution of Brain, Cognition, and General Intelligence, by David C. Geary, 2005 because it not only discusses some of the latest research on human intelligence, but...
Does anybody know what is the transmittivity (light) of the brain, and how do you find that out?
I am starting an experiment to image the inside of the mouse brain and most of the methods that I know of rely on external imaging techniques. Any reference for in vivo imaging of the brain...
i have tow questions from eth question list which I think will be present in this exam..Would you please tell me
1.when teh babies brain will be formed in mothers ?
2.if any, how a smoking mother would afftec her child's brain at that time ?
Thank you so very much if you could offered me...
BRAIN TEASER 1:
In this long post,
where would the
the brain teaser
be?
BRAIN TEASER 2:
Bob is Ray, and I am not Tom, Evaa is Sam, ever is Sam me?
Hint:
Tri notes read mind joker.
Hint to that, I just wrote: Synonym.
(Skip iSSamME)
Okay, I was bored. I just want to see if anyone...
A man wants to get through to the another room. There are two doors up for the option of entering into the room the man wants into. However, there is a guard in front of each door. One of the guards always tells the truth, and the other guard always lies. How can the man determine which door...
a man has two bottles, each containing ten pills. in order to stay alive, he must take two pills (one from each bottle) simlutaneously in order to stay alive. any other combination is fatal. unfortunately, he spills both bottles, and as a reslut has 2 pills in one bottle and none in the other...
please, i need input
this is my first post in this forum, so hello everyone. :biggrin: i'd like to say that i have never really had experience in philosophy so if anyone recognizes my thoughts as someone elses theory then please tell me so i can look into it.now to the real stuff. I would...
One of the amusements at many carnivals is a rotating cylinder. The customers step inside and stand with their backs to the wall. The cylinder spins very rapidly, and at some angular velocity the floor is pulled away. The thrill-seekers now hang like flies on the wall. If the radius of the...
The Brain of Einstein, a Question
I have a foggy understand of Special Relativity, and understand that it was understood previously without a real theory by Lorenz, but the General Theory was such a shot coming out of nowhere, without physical validation, that is impossible to understand the...
http://www.sciencedaily.com/releases/2004/10/041022104658.htm
a few thousand individual cells, rat neurons, placed on a Petri dish with 60 built-in electrodes, spontaneously connect themselves to form a neural network which is capable of controling things*
and modifying its behavior as a...
So just how did the brain come into existence physically? ... To exploit an available resource perhaps? :wink: Which, I think is the whole point, why does anything evolve, if not to exploit the resources at hand? Why did our eyes elvolve, if not to exploit the available source of light? What...
Please someone help me with these brain teasers, Thanks! I have try to answer these problem, but I don't know whether they are right or wrong. PLEASE HELP! :cry:
A hill is one mile from the bottom to the top and then one mile from the top to thebottom. A person drives a car from the bottom...
Please someone help me with these brain teasers, Thanks! I have try to answer these problem, but I don't know whether they are right or wrong. PLEASE HELP! :cry:
A hill is one mile from the bottom to the top and then one mile from the top to thebottom. A person drives a car from the bottom...
I hope this question doesn't sound too stupid but is the brain really gray? That is, is the brain tissue itself gray in appearance? If it is, why is it?
If it is, is it the only human organ that is Gray?
I'm going to muscle my way in on the quiz action with the following quiz about the island of Great Britian (hopefully not too hard):
1) What is the name of the archetypal country gent, often depicted as wearing a waistcoat with the Union Jack emblazoned on it, used to represent England in...
A shooter aims directly at a target on the same level 200 m away.
a) If the bullet leaves the gun at a speed of 250 m/s, by how much will it miss the target?
b) At what angle should the gun be aimed so the target will be hit?
On average, how many calories (approx.) does the brain need during the course of a day? Does more activity (thinking more than normal) cause an increased need for calories? How many calories are used while sleeping?
Thanks,
Jacob
I have a box when suspended from a cable in a vacuum is 4450N and is .608m wide (it's also a cube).
W = 4450N = T1 (tension on the cable)
V = 0.2248m^3
When I suspend it into a liquid, L/2 m from the surface, of density 944 kg/m^3, I want to know the buoyant force, the new tension of the...
I've got a U-tube filled with Mercury and water. If I add 11.2 cm of water to the left side, how much does the mercury rise on the right side?
For simplicity's sake, D will stand for density, p0 for initial pressure, w = water, m = mercury, h = 11.2 cm for the water and d = the distance the...
What are the effects on the brain from hashish could anybody tell me?
From the stage that one is stoned to the stage that the stoned feeling has decayed.
And are there any long term effects from this substance? Does it really kill off brain cells for good?
And why do you become so creative...
A boat is docked at a shore. A ladder is hanged from top of the boat So that the last step is touching the water. The distance between steps is 20 cm and there are 4 steps in the ladder. A tide is raising the water-level 5 cm a min. How long will it take for the water to reach the top step.