Is there one nostril that leads to the brain and one that leads to the body?

Nasal cavity. There is no direct connection to brain from the nostrils, but at the top of the nasal cavity which forms the floor of the olfactory nerve bulbs, the fibers of the olfactory bulbs inter the nasal cavity through the cribiform plate of ethmoidal sinus on each side of the midline, any frcture of the skull base in the frontal region caused the CSF to drip into the nasal cavity cause CSF nasal disharge.