Anatomy And Physiology

Anatomy Physiology

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"Anatomy Physiology"
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In the 1960's, John D. Fitzgerald wrote an amusing series of books about a main character whose nickname was "The Great Brain". This young boy could figure his way out of any problem, plot ways to amass great wealth, develop elaborate schemes to either get his two brothers in trouble or to do his chores, and yet sometimes choose to be kind-hearted or generous. The brain gives us the capability to be loving, to analyze, to remember, and even to scheme but does so much more than that.

When we are born, our brains weigh less than a pound. By the age of six, our brains will have just about tripled that weight. That weight is about one-sixth the weight of an elephant's brain and about 170 times the weight of a squirrel's brain. The approximately one hundred billion neuron cells with which we are born increase in size and develop several nerve connections in the first six years of life. Think about the vast amount of information a child accumulates, analyzes, stores, and retrieves moment by moment from the minute she is born to the day she enters kindergarten. That is quite an impressive amount of data and interconnecting frameworks of information. Our brains are the marvels responsible for this unseen library in us.

Our brains also allow us to determine through our sense of taste whether the Thanksgiving pumpkin pie is perfect or is missing a key ingredient. What would a symphonic music concert be without our ability to process what we hear and see and decide if a player or a section of the orchestra has performed a piece well or played sour notes? Through intricate nerve relays, our brain receives and deciphers a sensation and then tells our muscles to react when we accidentally touch a teakettle with boiling water in it.

Our hearts would stop beating, we would forget to breathe or sleep, our eyeballs would dry out for lack of blinking, and the organ systems of our bodies would simply cease to function if not for the work of the medulla, or brain stem. When was the last time you had to say to your stomach, "Digest that hero sandwich I just ate." Researchers looked at the development of the medulla when trying to solve the puzzling question of what causes SIDS (Sudden Infant Death Syndrome) in some babies but not in others.

Thinking about the connection between our brains and oxygen, did you know that 20% of all the oxygen our bodies take in is directed to the brain? In fact, if our brains are deprived of oxygen for three to five minutes parts of the brain begin to die. Ten minutes of oxygen deprivation will cause irreparable brain damage. The one thing that seems to be an exception to this is when a person's body becomes hypothermic: the cold seems to "preserve" the brain for up to forty minutes with minimal damage. Blood flow to the brain is extremely important because of the oxygen and glucose that the brain requires to function well. Of the total blood flow in the body, 20% is directed toward the brain. If the blood flow to your brain was interrupted for eight to ten seconds, you would faint.

As important as our brain is to our existence, it is designed with rather effective protection. Rap the top of your head and you will feel bone. The cranium, or skull cap, on top of the head encases the brain. Shake your head vigorously. Do you hear sloshing? Actually you wouldn't because a watery liquid fills the extra spaces, tunnels and cavities of the brain and the spinal cord. This liquid is called cerebrospinal fluid. Our brain and spinal column contain about 4 ounces, or a half cup, of this fluid. The final protection is one that screens the blood to keep many chemicals that could be injurious from damaging the brain and its cells.

Surprisingly, the brain itself has no cells that register pain. That allows researchers to conduct experiments in mapping out speech and emotion areas of the brain on fully conscious patients.

Michelangelo acknowledged the seat of the human intellect, the brain, when he painted the Sistine ceiling panel we call the "Creation of Man", according to Dr. Frank Lynn Meshberger. Meshberger, who is a physician at St. John's Medical Center in Anderson, Indiana, believes the cloak and angels surrounding God as He extends His finger to Adam show an outline of the major parts of the human brain. Interesting symbolism, if it was Michelangelo's intent.

You remember Hercule Poirot, the Belgian detective created by Agatha Christie? He constantly referred to exercising his "little grey cells" to solve a mystery. The grey cells compose only 5% of the total brain and if unfolded and laid out on a desk top, would cover it. The rest of the brain is the synapses that run between the gray cells to produce a path of communication between the brain and all of the parts of the body.

According to Steve Gillam of, about 85,000 brain cells die each day, a tiny fraction of the total amount we have. If you use your brain each day in puzzle-solving, reading, researching, or learning, in other words, stimulating your brain, it will produce new neurons in response to handle the demand of what you are doing. Only seven facts can be kept at one time in your short term memory and even some long term memory items must be "cleared" so that new information may be added. It seems "lifelong learning" is the key to keeping the human brain healthy and fit.


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