| Our bodies are wonderful machines. They do and | | | | in pH and other agents having what are called |
| accomplish literally billions of activities that day and | | | | "high molecular weight." |
| almost all of these activities come off with 100% | | | | The barrier has been so completely evolved that |
| accuracy almost every single time. Through | | | | it is able to allow fat-soluble, lighter weight |
| millions of years of evolution -- which is basically | | | | substances, for the most part, to pass through. |
| nature's way of engaging in trial and error | | | | Very specific water-soluble amino acids are also |
| experimentation on a grand scale -- our bodies | | | | allowed to pass through this barrier to facilitate |
| have learned what works and what does not. | | | | certain other neurochemical reactions and that is |
| Because of this experimentation there are | | | | about all that is allowed to make the journey |
| mechanisms within our body that keep us safe | | | | when the blood/brain barrier is working in good |
| from harm, both outside our bodies and from | | | | order. That is also why -- unless the exposure to |
| within our bodies. | | | | the heavy metal is very large -- this barrier can |
| One such mechanism is what scientists and health | | | | work to shuttle outward any mercury that has |
| professionals refer to as the "blood/brain barrier." | | | | managed to make its way up to the barrier itself. |
| This type of figurative wall acts as a kind of | | | | As an adjunct part of the classic blood/brain |
| gatekeeper that prevents harmful chemicals or | | | | barrier, another part of the body -- called the |
| even minor changes in the blood's chemistry and | | | | choroid plexus -- works in a similar manner to |
| pH balance from overly affecting the brain | | | | restrict the flow between blood vessels like |
| through a mechanism that has proven to be | | | | capillaries and the body's cerebral spinal fluid (CSF). |
| highly resistant to certain water-soluble chemicals | | | | This serves a dual purpose of not only protecting |
| that could make their way into the brain and the | | | | precious cerebral spinal fluid from harm but also |
| fluid surrounding it and which would lead to | | | | works in conjunction to add just a bit more |
| ultimate physical harm. | | | | protection for the body's most precious organism, |
| Such chemicals or substances are fairly well | | | | the brain. |
| known, including heavy metals such as mercury. | | | | For the layman, it might be helpful to think of a |
| This kind of exposure to mercury can lead to a | | | | series of increasingly robust filters through which |
| wide range of neurological deficit disorders when | | | | contaminated water must pass. At the end of |
| the metal makes it through the blood/brain barrier | | | | that filtration cycle pure, fresh water emerges. |
| due to weakness of the barrier or dysfunction | | | | These filters, the openings -- or pores -- which |
| which has created the conditions where heavy | | | | become increasingly smaller as the filters get |
| metals, chemicals or changes in blood and fluid pH | | | | closer to the tap or outlet where the final product |
| are present. Evolutionary processes work to keep | | | | will emerge would be self repairing and constantly |
| the brain pH levels tightly controlled as possible | | | | replenished in a system that resembles how the |
| while also working to prevent any exposure of | | | | body utilizes its own blood/brain barrier. |
| the brain to toxic agents. | | | | Clinicians and physicians have certain tools and |
| As a physical entity, the blood/brain barrier is | | | | tests available to them to assess whether or not |
| comprised of a vast array of what are called "end | | | | the barrier is functioning at optimal levels. They |
| brain capillaries," each of which benefit from a | | | | usually employ these tests when a person begins |
| seamless and of very tightly knitted junctions that | | | | to demonstrate what they call "neurological |
| are enclosed even more tightly by a type of | | | | deficit." They will examine the presence or |
| connective tissue. Working together, these | | | | non-presence of certain proteins or normally |
| networks form a highly restrictive barrier, for all | | | | benign chemicals that will give a specialist in idea of |
| intents and purposes that act to prevent the brain | | | | how well the blood/brain barrier is working at that |
| from being affected by even very minor changes | | | | particular moment in time. |