Nervous System Neuroscience Can Be

¶ … Nervous System

Neuroscience can be a difficult subject for the layperson or the student who is not majoring in deep science and biology. But the body's central nervous system plays such an important role in humans' lives -- and has key psychological affects -- it is important to break down the subject for clear understanding. This paper will review the main aspects of the human central nervous system, and also point to how the central nervous system of police officers can be affected by the stressful, dangerous work they do.

What is the central nervous system? Washington University science professor Eric Chudler has published a descriptive online chapter explaining the central nervous system, its parts, how it works and why it is important. The nervous system in humans is broken down into two parts -- the central nervous system and peripheral nervous system.

Central Nervous System: The central nervous system is divided into parts that include the brain, and the spinal cord. How much does the brain way -- how big is it? Typically, the human brain weighs about three pounds, Chudler explains. But inside that three-pound brain about "about 100 billion nerve cells" (called neurons); and also there are to be found in the human brain "trillions of 'support cells' called glia.

Compared with a human brain, a dinosaur (in this case, a stegosaurus dinosaur) had a brain weighing only about 70 grams, that represented about 0.004% of its body weight. The human brain represents about 2% of its body weight. Presumably, this ratio is presented in the science to show that humans have far more intelligence than these giant creatures that lived millions of years ago.

While the spinal cord of a typical woman is about 43 centimeters, an adult man's spinal cord is about 45 centimeters long. The spinal cord and all of its delicate features is protected by the "vertebral column" which is basically the backbone. The backbone protects the spinal cord. Basically, the spinal cord carries messages from the brain up and down the body -- relaying responses and instructions for important bodily functions.

The brain is divided into two hemispheres and each one "communicates with the other through the corpus callosum" which is a bundle of nerve fibers (Washington University). Within those hemispheres are neurons (called "nuclei") and there are axons (called "tracts") (Chudler, 2006). (http://faculty.washington.edu/chudler/nsdivide.html).

The brain has a Cerebral cortex that controls a person's perception, reasoning, language, voluntary movement and thought. What is the cortex made of? Chudler describes the cortex as "a sheet of tissue that makes up the outer layer of the brain" and it is from 2 to 6 millimeters thick. To look at a human cerebral cortex one sees an object that has "many bumps and grooves"; a bump is called "gyrus" and A cortex groove are called a "sulcus."

Another important part of the brain is the Cerebellum; it controls a person's body movement, balance, and posture. The Brain stem controls breathing, heart rate, and blood pressure. The Hypothalamus has control over body temperature, emotions, hunger, thirst, and "circadian rhythms" (Washington University). The Midbrain also has some important functions -- such as controlling vision, audition, body movement and eye movement. Without becoming to complicated and scientific, this paper will conclude this section with three more brain parts that provide key human functions. The Thalamus receives "sensory information and relays this information to the cerebral cortex" (Chudler); the Limbic System helps humans control the "emotional response to a given situation" and also controls memory; and the Hippocampus is important for a person's memory and learning processes.

What To Do With Dead Neurons: Earlier in the paper it was explained that the brain has about one hundred billion neurons. The Vanderbilt Medical Center's weekly newspaper (Reporter) points out an interesting problem that is related to those neurons. During the growth of the nervous system there are many more neurons produced by the body than will ever be needed. What happens is this over production of neurons results in a kind or "pre-programmed 'suicide' mechanism called apoptosis" (Marino, 2010). So if the brain kills off these neurons on purpose, what happens to the dead neurons? Journalist Melissa Marino asserts that the body must dispose of the dead neurons or else the body's immune system is in trouble.

Interestingly, Dr. Bruce Carter (a biochemistry professor) of Vanderbilt has discovered the brain's "clean-up crew" and the protein that is important to that clean-up crew (disposing the dead neurons) is called "jedi-1" (not to be confused with the science fiction movie "Star Wars"). If jedi-1 is not doing its job, the body may suffer from "autoimmune conditions." So there are many interesting things going on with our central nervous system that most people aren't aware of, but are important for good physical and psychological health.

Childhood Survivors of Central Nervous System Cancer Suffer Later: Another article related to the central nervous system, published in Science Daily, reports that children who suffered from cancer of the central nervous system (brain cancer in many instances) have a problem in school later in life. In fact they "achieve lower-than-expected educational success compared with the general public," Science Daily reports, based on an article in the Journal of the National Cancer Institute.

Children who had central nervous system cancer and were treated with radiation "performed worse than the general population," according to a study of 10,000 5-year survivors conducted by the University of Birmingham in the UK.

Stresses of Police Work: Harold E. Russell and Allan Beigel published the book Understanding Human Behavior for Effective Police Work, a helpful tool for those wishing to relate to law enforcement-related psychological stress and how it effects the central nervous system. When a police officer encounters a dangerous or threatening situation, he reacts much like primitive man when confronted by a large animal, Russell et al. explain (Russell, 1990, p. 346). The nervous system automatically secretes "more adrenaline," the person's breathing changes into a more rapid breathing, digestion "dramatically" stops, the spleen produces more red blood cells so more oxygen can be carried through the body.