where is the olfactory nerve located in the brain
Olfactory nerve The afferent nerve fibers of the olfactory receptor neurons, transmit nerve impulses about odors to the central nervous system, where they are perceived by the sense of smell (olfaction). Derived from the embryonic nasal placode, the olfactory nerve is somewhat unusual among cranial nerves because it is capable of some regeneration if damaged. The olfactory nerve is sensory in nature and originates on the olfactory mucosa in the upper part of the nasal cavity.[1] From the olfactory mucosa, the nerve (actually many small nerve fascicles) travels up through the cribriform plate of the ethmoid bone to reach the surface of the brain. Here the fascicles enter the olfactory bulb and synapse there; from the bulbs (one on each side) the olfactory information is transmitted into the brain via the olfactory tract.[2] The fascicles of the olfactory nerve are not visible on a cadaver brain because they are severed upon removal.[3] :548
Hypoglossal nerve The hypoglossal nerve arises as a number of small rootlets from the front of the medulla, the bottom part of the brainstem,[1][2] in the preolivary sulcus, which separates the olive and the pyramid.[3] The nerve passes through the subarachnoid space and pierces the dura mater near the hypoglossal canal, an opening in the occipital bone of the skull.[2][4]