english: If you think about it, using the outsides of these blood vessels like this is a really clever design solution, because the brain is enclosed in a rigid skull and it's packed full of cells, so there is no extra space inside it for a whole second set of vessels like the lymphatic system.
non_english: Korišćenje spoljašnjosti krvnih sudova je zapravo veoma dobro rešenje, pošto je mozak okružen čvrstom lobanjom i sasvim popunjen ćelijama, tako da u njemu nema prostora za dodatnu mrežu sudova kao što je limfni sistem.