The pathophysiology of falling.

The gravitational pull of the earth 
isn't responsible for people 
falling in love.

Not any amount of
endorphins and pheromones
could explain. 

Not even a number of hearts skipping b e a t s.

When you fall...

YOU JUST DO.

Ergo, a specific love pathophysiology-wanna-be does not exist. It varies from person to person, and relationship to relationship.