The Brain .What weighs about three pounds but has more parts than there are stars in the Milky Way galaxy? What fills the space occupied by only three pints of milk yet includes components that, laid end to end, would stretch several hundred thousand miles? What looks like an oversized walnut made of soft, grayish-pink cheese but contains the equivalent of 100 trillion tiny calculators? What, according to James Watson, co-discoverer of the helical structure of DNA, is “the most complex thing we have yet discovered in our universe”?
To all four of these intriguing questions there is but one surprising answer: the human brain. This miraculous organ is remarkable in its structure, its function, and its chemical composition. What is the brain? According to Richard Restak, the human brain is the master control center of the body. The brain constantly receives information from the senses about conditions both inside the body and outside it. The brain rapidly analyzes this information and then sends out messages that control body functions and actions. “Brain” 561) According to Tether, the brain is divided into three main parts: the cerebrum, the cerebellum, and the brain stem. These parts, in turn, are largely made up of nerve cells, called neurons, and helper cells, called glia. Researchers have discovered that there may be as many as 100 billion neurons in the brain and a far greater number of glia, possibly as many as one trillion . Important discoveries throughout the decade of the 1990’s in molecular biology and genetics are revolutionizing our understanding of how the human brain works.
Advances in imaging technology are allowing us to learn more about the human brain than ever before in human history. Keith A. Johnson and J. Alex Becker have even placed “The Whole Brain Atlas,” which consists of dozens of images of the brain in normal, damaged, and diseased states, on the World Wide Web for anyone with access to the Internet to view and study. One area of the new brain research reveals that the first three years of a child’s life are crucial to the development of the brain.
Proper stimulation of infants can according to Kotulak, affect the development of language, vision, brain power,aggression, emotions, touch, and education. Every animal you can think of — mammals, birds, reptiles, fish, amphibians — has a brain. But the human brain is unique. Although it’s not the largest, it gives us the power to speak, imagine and problem solve. It is truly an amazing organ. The brain performs an incredible number of tasks including the following: It controls body temperature, blood pressure,heart rate and breathing.
It accepts a flood of information about the world around you from your various senses (seeing, smelling, hearing, touching, tasting,etc. ) It handles your physical movement when walking, talking, standing or sitting. It lets you think, dream, reason and experience emotions. All of these tasks are coordinated, controlled and regulated by an organ that is about the size of a small head of cauliflower. Your brain, spinal cord and peripheral nerves make up a complex, integrated information-processing and control system known as your central nervous system.
In tandem, they regulate all the conscious and unconscious facets of your life. The scientific study of the brain and nervous system is called neuroscience or neurobiology. (Robynne Boyd) We’ll examine the structures of the brain and how each section controls our daily functions, including motor control, visual processing, auditory processing, sensation, learning, memory and emotion. Your brain is made of approximately 100 billion nerve cells, called neurons.
Neurons have the amazing ability to gather and transmit electrochemical signals — think of them like the gates and wires in a computer. Neurons share the same characteristics and have the same make up as other cells, but the electrochemical aspect lets them transmit signals over long distances (up to several feet or a few meters) and send messages to each other. Neurons have three basic parts: Cell body or “Soma”– This main part has all of the necessary components of the cell, such as the nucleus (which contains ), DNA plasmic reticulum and ribosomes (for building proteins) and mitochondria (for making energy).
If the cell body dies, the neuron dies. Axon– This long, cable-like projection of the cell carries the electrochemical message (nerve impulse or action potential) along the length of the cell. Depending upon the type of neuron, axons can be covered with a thin layer of myelin sheath, like an insulated electrical wire. Myelin is made of fat and protein, and it helps to speed transmission of a nerve impulse down a long axon.
Myelinated neurons are typically found in the peripheral nerves (sensory and motor neurons), while non-myelinated neurons are found in the brain and spinal cord. Dendrites or nerve endings– These small, branch-like projections of the cell make connections to other cells and allow the neuron to talk with other cells or perceive the environment. Dendrites can be located on one or both ends of the cell. (Craig Freudenrich PhD) We little by little ascended from decrease life types to what we are right now, by a process of natural choice from randomly happening adjustments.
Every modify had to prove its price by surviving the continual battle for existence, currently being in opposition to becoming, species towards species and this procedure has gone on for numerous hundreds of thousands of several years. You have been entrusted with the care and feeding of the most extraordinary and complex generation in the universe. Residence to your head and individuality, your brain houses your cherished reminiscences and future hopes. It orchestrates the symphony of consciousness that gives you function and passion, motion and emotion. Greg Sander) As far as we know the human mind advanced in three principal levels. Its historic and primitive aspect is the innermost core reptilian mind. It developed the mammalian mind by incorporating new features and new strategies of controlling the physique. Then progressed the 3rd portion of the mind, the neocortex, the Grey matter, the bulk of the brain in two symmetrical hemispheres, individual but communicating. To a significant extent it is our neocortex which makes it possible for us to behave like human beings.
So the human mind is composed of these a few various but interconnected brains and the way in which these 3 brains interact with each and every other underlies human behavior. The region of the brain that controls motion is in a quite slim strip that goes from around the top of the head correct down along exactly where your ear is found. It really is named the motor strip. If I injure that area, I’ll have difficulties managing 50 % of my human body. If I have a stroke in the left hemisphere of my mind, the suitable side of the physique will halt doing work.
If I have an injury to my appropriate hemisphere in this area, the left facet of my physique stops functioning (remember, we have two brains). This is why one particular 50 % of the confront may droop when a man or woman has had a stroke. Sophisticated mind-imaging techniques allow scientists to keep track of mind functionality in living people and to see how numerous areas of the mind are used for various varieties of projects. This is opening up worlds of information about brain perform and how it improvements with age or ailment. (Dr.
Greg Sander) As you read the words on this page, you are utilizing thousands of the 100 billion (more or less) nerve cells that make up your brain. The electrical firings and chemical messages running between these cells, called neurons, are what produce our thoughts, feelings and interactions with the world around us. One hundred billion neurons may seem like a lot of nerve cells, but is actually only about 20% of the number we originally start with. The number of nerve cells in our brain peaks prenatally and then they start to prune themselves out, one by one, through childhood.
By the time we enter adolescence, our brain has chosen the final select neurons it will keep throughout our adult life. The decision is based on which cells we use and which we do not. The cells we do not use are pruned away leaving more room to add branches, or dendrites, to the nerve cells that we do use. New branches are added as the brain receives and processes any new information. (Author Kathie Nunley) How does the brain actually “prune” the garden? The answer lies in a number of chemicals and their actions and reactions.
The chief pruner is probably an enzyme named Calpain. Calpain has the ability to self-destruct a cell. Technically this is known as autolysis (“auto” meaning self, and “lysis” meaning to destroy). Calpain is produced in the nerve cells when there is a heavy calcium ion concentration in their surrounding environment. Reduced blood flow can cause this high calcium ion build up between and within cells (for you biology enthusiasts, the calcium comes from the mitochondria and the ER as well as an influx from outside the cell).
In other words, high activity in a brain region calls for heavy blood flow to service the cells, low activity requires little blood flow. Therefore, the less-used areas, with their limited blood flow activity, tend to build up calcium ions. This build-up triggers the secretion of the enzyme Calpain, which causes the nerve cell to self -destruct. New growth, on the other hand, comes in the dendrite development, or branching of well-used neurons. This branching is caused from chemicals known as Neurotrophins.
Neurotrophins are a group of proteins which are responsible for the growth and development of neurons. As you may suspect, we use a lot of neurotrophins during childhood as the brain has massive growth and development. But we continue to use neurotrophins all of our lives, especially in the hippocampus area, the brain region responsible for new learning and new memory formation. There are many neurotrophins at work in the brain. The first one discovered is known as NGF (nerve growth factor).
Others, discovered since, have equally self-explanatory names as brain derived neurotrophic factor (bFGF), and glial cell-line derived neurotropic factor (GDNF). These neurotrophins work by attaching themselves to receptor sites on nerve cells and causing the cell membrane to change shape, grow and branch. ( Dr. Kathie Nunley) The research on brain wiring and the biology behind it continues to be a fascinating topic. It gives hope to people with stroke damage, Alzheimer’s and other neurological problems, as well as providing a better understanding for those of us who parent and teach young brains. Kathie F Nunley) Realizing the need for a concerted multidisciplinary effort to unravel brain structure and function and moreover provide better understanding of the path-physiology of neurological and mental disorders, the National Brain Research Centre (NBRC) was established under the aegis of the Department of Biotechnology, Government of India. Its new campus at Manesar in Haryana, 40 km from Delhi was inaugurated on December 16, 2003 by the President of India, A P J Abdul Kalam. ( Soumya Iyengar) Works Cited: Unravelling human brain Nandini Singh and Soumya Iyengar ttp://articles. timesofindia. indiatimes. com/2004-02-09/education/28333345_1_brain-disorders-human-brain-brain-function How Your Brain Works By Craig Freudenrich, Ph. D. And Robynne Boyd http://science. howstuffworks. com/environmental/life/human-biology/brain. htm The Human Brain By: Greg Sander http://www. articlebrain. com/Article/The-Human-Brain/471689 Brain Biology: it’s basic gardening. By Kathie F Nunley http://help4teachers. com/gardening. htm How the Human Brain Developed and How the Human Mind Works by Manfred Davidmann http://www. solhaam. org/articles/humind. html#THB