standing upright, a giraffe's head is around 1.5m above its heart. what excess pressure does this imply for cerebral blood compared to that just leaving the heart?
what is the weight of a column of water 1.5m tall?
weight/area=pressure=mg/area=density*volume*g/area=density*height*g
=10^3 * 9.8*1.5 N/m^2
and of course, N/m^2 is a Pascal