| ANOTHER superb organ is the human brain. It, | | | | “play back” these sights and sounds, along |
| together with the rest of the nervous system, is | | | | with thoughts and other sensations that no |
| often compared to man-made computers. Of course, | | | | man-made machine can record. |
| computers are constructed by humans and operate | | | | Human memory is still a mystery. It has something to |
| according to step-by-step instructions predetermined | | | | do with the way neurons connect. “The average |
| by human programmers. Yet, many people believe | | | | brain cell,” explains Karl Sabbagh in his book The |
| that no intelligence was responsible for | | | | Living Body, “links up with about 60,000 others; |
| “wiring” and “programming” the | | | | indeed some cells have links with up to a quarter of a |
| human brain. | | | | million others. . . . The human brain could hold at |
| Although extremely fast, computers handle only one | | | | least 1000 times as much information in the |
| piece of information at a time, whereas the human | | | | pathways connecting its nerve cells as is contained in |
| nervous system processes millions of pieces of | | | | the largest encyclopedia say 20 or 30 big |
| information simultaneously. For example, during a stroll | | | | volumes.” |
| in the springtime, you can enjoy the beautiful | | | | But how does one neuron pass information to |
| scenery, listen to the song of birds, and smell the | | | | another? Creatures with a simple nervous system |
| flowers. All these pleasant sensations are transmitted | | | | have many nerve cells that are joined together. In |
| simultaneously to your brain. At the same time, | | | | such a case, an electrical impulse crosses the bridge |
| streams of information flow from the sense | | | | from one neuron to the next. The crossing is called |
| receptors in your limbs, informing your brain of the | | | | an electrical synapse. It is fast and simple. |
| moment-to-moment position of each leg and the | | | | Strange as it may seem, most neurons in the human |
| state of each muscle. Obstacles in the footpath | | | | body pass messages via a chemical synapse. This |
| ahead are noticed by your eyes. On the basis of all | | | | slower, more complex method can be illustrated by a |
| this information, your brain ensures that each step is | | | | train that reaches a river without a bridge and has to |
| taken smoothly. | | | | be ferried across. When an electrical impulse reaches |
| Meanwhile, the lower regions of your brain govern | | | | a chemical synapse, it has to stop because a gap |
| your heartbeat, breathing, and other vital functions. | | | | separates the two neurons. Here the signal is |
| But your brain handles much more. As you walk, you | | | | “ferried” across by the transfer of chemicals. |
| can sing, talk, compare present scenes with past | | | | Why this complex electro-chemical method of passing |
| scenes, or make plans for the future. | | | | nerve impulses? |
| “The brain,” concludes The Body Book, | | | | Scientists see many advantages in the chemical |
| “is much more than a computer. No computer | | | | synapse. It ensures that messages pass one way. |
| can decide that it is bored or wasting its talents and | | | | Also, it is described as plastic because its function or |
| should embark on a new way of life. The computer | | | | structure can easily change. Here signals can be |
| cannot drastically alter its own program; before it | | | | modified. Through use, some chemical synapses get |
| sets out in a new direction, a person with a brain | | | | stronger while others disappear because of disuse. |
| must reprogram it. . . . A computer cannot relax, or | | | | “Learning and memory could not develop in a |
| daydream, or laugh. It cannot become inspired or | | | | nervous system that had only electrical |
| creative. It cannot experience consciousness or | | | | synapses,” states Richard Thompson in his book |
| perceive meaning. It cannot fall in love.” | | | | The Brain. |
| The Most Wonderful Brain of All | | | | Science writer Smith explains in his book The Mind: |
| Animals such as elephants and some large sea | | | | “Neurons do not just fire and not fire . . . they |
| creatures have brains larger than that of a human, | | | | must be capable of passing on much more subtle |
| but in proportion to body size, the human brain is the | | | | information than yes or no. They are not just |
| largest of all. “The gorilla,” explains Richard | | | | hammers hitting the next nail, either more frequently |
| Thompson in his book The Brain, “is physically | | | | or less so. They are, to complete this analogy, a |
| larger than a human yet has a brain only one-fourth | | | | carpenter’s kit, with screwdrivers, pliers, pincers, |
| the size of the human one.” | | | | mallets and hammers. . . . Each neural impulse is |
| The number of different pathways between neurons | | | | transformed along the way, and nowhere else than |
| (nerve cells) in the human brain is astronomical. This is | | | | at the synapses.” |
| because neurons have so many interconnections; one | | | | The chemical synapse has a further advantage. It |
| neuron may connect up with over one hundred | | | | takes less space than an electrical synapse, which |
| thousand others. “The figure of possible | | | | explains why the human brain has so many synapses. |
| connections within our modern brain is as good as | | | | The journal Science gives a figure of |
| infinite,” states Anthony Smith in his book The | | | | 100,000,000,000,000 equivalent to the number of |
| Mind. It is larger “than the total number of atomic | | | | stars in hundreds of Milky Way galaxies. “We are |
| particles that make up the known universe,” says | | | | what we are,” adds neuroscientist Thompson, |
| neuroscientist Thompson. | | | | “because our brains are basically chemical |
| But there is something even more remarkable. It is | | | | machines rather than electrical ones.” |
| the way this vast network of neurons has been | | | | |
| connected that enables humans to think, speak, | | | | Why Your Brain Needs So Much Blood |
| listen, read, and write. And these things can be done | | | | BEFORE diving into a swimming pool, perhaps you dip |
| in two or more languages. “Language is the | | | | your toes into the water. If the water is cold, tiny |
| crucial difference between humans and animals,” | | | | cold receptors in your skin quickly respond. In less |
| states Karl Sabbagh in his book The Living Body. | | | | than a second, your brain registers the temperature. |
| Animal communication is simple by comparison. The | | | | Pain receptors can transmit information even more |
| difference, admits evolutionist Sabbagh, “is not | | | | quickly. Some nerve impulses reach speeds of 225 |
| just a trivial improvement on other animals’ | | | | miles [360 km] per hour comparable to running the |
| abilities to make noises it is the fundamental property | | | | length of a football field in one second. |
| that makes humans human, and it is reflected in | | | | How, though, does the brain work out the intensity |
| major differences in brain structure.” | | | | of a sensation? One way is by the frequency with |
| The marvelous structure of the human brain has | | | | which a neuron fires; some fire a thousand or more |
| motivated many to make better use of its potential | | | | times a second. The intense activity that takes place |
| by becoming skilled at some trade, learning to play a | | | | among neurons in the brain would be impossible were |
| musical instrument, mastering another language, or | | | | it not for the work of pumps and powerhouses. |
| developing whatever talents add joy to life. | | | | Each time a neuron fires, atoms with an electrical |
| “When you learn a new skill,” write Drs. R. | | | | charge pour into the cell. If these sodium ions, as |
| and B. Bruun in their book The Human Body, | | | | they are called, are allowed to accumulate, the |
| “you are training your neurons to connect in a | | | | neuron will gradually lose its ability to fire. How is the |
| new way. . . . The more you use your brain, the | | | | problem solved? “Every neuron,” explains |
| more efficient it will become.” | | | | science writer Anthony Smith in his book The Mind, |
| Made by Whom? | | | | “contains about a million pumps each one is a |
| Could something so highly organized and orderly like | | | | slight bump on the cell membrane and every pump |
| the hand, the eye, and the brain have come about | | | | can swap about 200 sodium ions for 130 potassium |
| by chance? If man is credited with inventing tools, | | | | ions every second.” Even when neurons rest, the |
| computers, and photographic film, surely someone | | | | pumps keep working. Why? To counteract the |
| should be honored for making the more versatile | | | | effect of sodium ions that leak into the cell and |
| hand, eye, and brain. “O Jehovah,” the Bible | | | | potassium ions that leak out. |
| psalmist said, “I shall laud you because in a | | | | The activity of the pumps requires a constant supply |
| fear-inspiring way I am wonderfully made. Your | | | | of energy. The energy comes from tiny |
| works are wonderful, as my soul is very well | | | | mitochondria, or “powerhouses,” scattered |
| aware.” Psalm 139:1, 14. | | | | inside each cell. To produce energy, each |
| Many wonderful functions of the human body take | | | | powerhouse needs oxygen and glucose supplied by |
| place without our conscious effort. Future post of | | | | the blood. No wonder your brain needs so much |
| this blog will discuss some of these amazing | | | | blood. “Although it constitutes only about 2 |
| mechanisms, and also whether aging, sickness, and | | | | percent of total body weight,” explains Richard |
| death can be conquered, so that we can enjoy life | | | | Thompson in his book The Brain, it “receives 16 |
| forever! | | | | percent of the blood supply . . . Brain tissue receives |
| Your Wonderful Neurons | | | | 10 times as much blood as muscle tissue.” |
| A NEURON is a nerve cell with all its processes. Your | | | | The next time you feel the temperature of water, |
| nervous system contains many types of neurons, | | | | be thankful for the trillions of pumps and |
| which total about 500 billion. Some are sense | | | | powerhouses in your brain. And remember that all |
| receptors that send information from different parts | | | | this activity is possible because of oxygen and |
| of the body to your brain. Neurons in the higher | | | | glucose transported by your blood. |
| region of your brain function like a video recorder. | | | | The human brain processes millions of bits of |
| They can permanently store information that comes | | | | information simultaneously. |
| from your eyes and ears. Years later you can | | | | |