Blood-Brain Barrier

As I read about the cells of the nervous system, anatomy of neurons and glia, the blood-brain barrier, nerve impulses, resting potential, myelin sheath, local neurons, and so on; everything seemed to so confusing at times but as i continued to read the most interesting thing to me was the Blood-Brain Barrier.

The Blood-Brain Barrier depends much on the endothelial cells, even though that on the outside of the brain cells are not closely knit but slightly separated yet in the inside they are so tightly knitted together that nothing get through.  The main purpose of the Blood-Brain Barrier is to keep both useful and harmful chemicals out, the useful chemicals being all fuels and amino acids which are the building blocks for protein.  For brain function it requires a very special mechanism to get these chemicals across the blood-brain barrier.

The brain consists of a few mechanisms that include uncharged molecules like oxygen and carbon dioxide that freely cross; water is able to cross through these protein channels in the endothelial cell wall just as molecules that dissolve in the fat of the membrane cross over passively.

The other chemicals that are transported to the brain do so by active transport it uses up energy to pump  the chemicals such as glucose, amino acids, purines, choline, iron, some hormones, and certain vitamins.

One major advantage of having blood-brain barrier is that it keeps viruses out but on the down fall it keeps out nutrients as well.  The blood-brain barrier is essential to everyone's health if there is ever a some kind of shrinking in the endothelial cell lining  harmful chemicals may enter the brain but just as the blood-brain barrier protects it may also prevent certain medication to cross over that might be life saving.