Olfactory nerves. Also known as CN1, the olfactory nerve is the first of 12 cranial nerves located within the head. It relays sensory data to the brain, and it is responsible for the sense of smell. The nerve's olfactory receptors are located within the mucosa of the nasal cavity. Unlike many other nerves, CN1 does not possess two trunks. Rather, its sensory fibers extend through the ethmoid bone's cribriform plate, a part of the skull located behind the nose.