Secondary Brain Tumors

Je'm reading a book on neuroscience and it says " the tumors of Primary brain present themselves in the brain, while metastatic (called so secondary) the brain tumors spread themselves somewhere else body by the sanguine current. "
But just some days ago, I learned that la 's a Barrier of Blood Brain that prevents from the things in the blood to attain the brain.
How, then, does a tumor attain the brain as treated above?
How it it is exempt to the BBB? Is Ai-t-j'interpredted poorly that the barrier? Does it prevent to enter just of the toxins and the bacteria or something?

A cell of metastatic is not a foreign substance it is part of persons possess the body that lost the capacity to stop growing. A cell of metastatic (that the body treats as normal) the can obstacle a turn anywhere in the body including to travel by the barrier of brain of blood in the brain. The body allows the passage because it recognizes the cell as is part of the body or it is cheated in the this is 'normal' if it allows the passage. In the barrier of brain of blood the brain is partitioned remainder of the body to protect it from the bacteria or other foreign question. . The sector is limited. . Lol. . Nevertheless this unfortunately prevents also A LOT OF medicines of thereapeutic or the chemotherapy to attain tumors. There are now some medicines that are rather small past throught the barrier of brain of blood. . But not enough.

http://en.wikipedia.org/wiki/blood-brain...

It does not do any doubt the barrier of brain of blood (BBB) exists does to treat it cancer in the so difficult brain as most of our drugs cannot cross the barrier. You did not interpret poorly that you read; the cancer spreads itself by the lymphatic ganglions or running it sanguine. The this is the remainder of your question that is lasts to reply. This belongs to the category of one of the a lot of things that we do not understand.

We did not discover even the barrier of brain of blood until the years 60. We know in the sectors where there is cancer the cells of endothelial are different vasculature of normal brain and the BBB is less intact. The vessels seem to reflect those of the fabric of origin of tumor instead of the cells of endothelial of CNS. We do not know just or why this arrives. The source (the sources) : I am a cancer clerk.