Question

The cells that compose the walls of the blood vessels in the brain are less tightly packed than those of the blood vessels serving the rest of the body.

True

False

Answer 1

Answer - False

There is a barrier between the blood vessels supplying the brain and the brain tissue. This barrier is called as blood brain barrier. It prevents various molecules from entering into the brain from blood. Only some selected small molecules, gases are allowed to pass through this barrier. It was seen that when a dye was injected into the body, the dye reached every tissue except brain. Few molecules requires special transporters to cross through this barrier. This barrier is due to "endothelial tight junctions". It restricts many harmful toxins and bacterias to enter the brain, which can lead to serious results.