The pineal gland has the shape of a pine cone, where his name that comes from the Latin "pinea "Who wants to say "pin".
Technically, the pineal gland is not part of the brain. It is not protected by the blood-brain barrier, in fact, it receives more blood than all the other bodies with the exception of the kidneys. As it is not protected from the blood stream, it accumulates mineral deposits, also called "cerebral sand". With time, this sand accumulation and produces the calcification of the gland, making opaque viscous and the fluid in the interior of the gland.