by Patrick Sharkey

Created on: November 04, 2010   Last Updated: November 07, 2010

Matter and consciousness; the brain and the effects of the brain, understanding this has been a fundamental task for philosophers for millennia, whether the souke of Aristotle, Cartesian dualism, Kan'ts transcendental idealism, psychology or neurology, it has never abated.  To understand how the brain works is to understand the microscopic and macroscopic functioning of the integrated system of neurons, and to understand the brains significance is to ask as to the nature of significance itself.

First a few fun facts about the brain.

The brain is composed of roughly 200 billion neurons, each with between 1 and 10,000 independent connections.

The amount of potential particles in the universe is 1 x 10e79 and the amount of potential pathways in the human brain is 1x10e1,000,000

What we are dealing with here is the most complex thing in the perceivable universe. 

Now for a brief summary of the working of the brain and why this is inadequate to explain the fact that we are conscious.

The basic neurone, though there are hundreds of subcategories, basically function on the same basic need to propagate an electrical impulse, and modify their own structure to modify the pulses which they give.  

The cell itself is composed of dendrites (which for the most part receive signal) and axons (which for the most part send signals), they are connected, apart from motor neurones in the peripheral nervous system and a few others, at the synapse.  

The electrical signals in the brain work different from a current, as in the displacement of electrons down a conductive material, they work based on a charge created by positively charged ions which surround and lie internally to the cell.  Chloride, Sodium, Calcium and Potassium are the principle ions.  We will take the basic model of Sodium and Potassium.  Sodium is in high extracellular (outside the cell) concentration, and potassium is in high intracellular concentration (inside the cell), this establishes a concentration gradient, essentially meaning that the sodium wants to enter the cell as there is a low concentration. When the electrical charge hits the cell membrane (the outer edge of the cell) it opens gates made of proteins which are selective to sodium ions, and allows the influx of sodium.  Now remember these are all positively charged ions, so once sodium and potassium are crowding the cell, they crowd it with a positive charge, which is then able to flow into the axon.

• 1
• 2
• 3
• Next Page >>