Medical Central: The Brain

It's time to check out the body's Control, Intelligence, and Head of Operation Center... the Brain!

The Brain
The Brain controls everything. It controls involuntary actions, sleep, hunger, and so on. And it's the part we use for thinking and making decisions. It's so important, the skull has a special part which protects it.
The Brain is our primary control center. There are actually a bunch of parts to it, all controlling different things. One part is actually a gland... the piturary (sp?) gland, which sends out hormones. These hormones control different stuff, like growth.
But there are three primary parts to the brain... the cerebrum, the cellebum (sp?), and the brain stem. The brain stem controls different involuntary actions... well, a lot of the brain does that. The cellebum (sp?) controls balance. And the cerebrum does a lot of stuff, including movement.
The cerebrum has two halves. For some unknown reason, the right half controls the left half of the body, and visa-versa! (sp?) And scientists think that these halves have specialities (sp?)... one half does more math and stuff, and the other specializes more in music and such stuff. But these two halves have a piece connecting them, so that each of them know what their counterpart is doing.
The brain is made of nerves (also known as neurons or neurones [sp?]). It is part of the nervous system, so that makes sense. It has nerves connected to it too, which it can control different parts of the body... and some don't even have to go down the other primary part of the nervous system (the spinal cord)! This is because some are connected directly to the face muscles, and some are connected to our arms and shoulders, so the visit into the spinal cord isn't always necessary.
There are three types of nerves... sensory neurons, motor neurons, and connector neurons. We can easily figure out sensory neurons... they're for carrying signals to the brain about our senses! Motor neurons are the ones that carry instructions to the muscles from the brain. And connector neurons are all the rest.
Nerves work by sending electrical signals. They receive them from the tentacles connected to the main body (which has its own control/processing center called the nucleus!), zap them down the protein-protected axon, then out the tentacles at the far end. Once the signal reaches here, neurons release a chemical, which the next neuron catches, translated into electricity, and zap! There goes the cycle all over again! But it happens extremely fast! Nerve signals move around 270mph! Whoa! So it makes sense that nerves receive a ton of signals! In a short amount of time, one nerve can receive about 100,000 signals! WOW!
Nerves are too small (or narrow) to see. Still, we know about the longest nerve... it goes from the spinal cord (which is part of the primary nervous system) to our toes! This nerve can be about 4 feet long! WOW!
Despite knowing how nerves work, we are still unsure totally of how the brain works. It's the best computer in existence... it does a zillion times better than any man-made computer today! The brain can compute, do calculations, make decisions, make memories, think, and control a ton of stuff... in less than a second! And this is all done by a bunch of connection-making and signal-sending and so forth by tons of nerves! The only computer that comes close to this organ is seen only in sci-fi movies and shows. Scientists are still studying the brain, and figuring out which part does what (brain scans helps), and so on.
And guess what? The part we use for thinking is only the surface of the cerebrum!!! It'll seem unlikely, but it's true! It's about 0.1 inch thick in most places, but this wrinkly brain-surface is pretty big. When spread out, it's as big as a newspaper! Wow!