Which cranial nerve is primarily responsible for the sense of smell?

The olfactory nerve is primarily responsible for the sense of smell. This cranial nerve is specifically designed to transmit sensory information related to olfaction, which occurs when odor molecules bind to receptors in the nasal cavity. The olfactory nerve fibers extend from the olfactory bulbs in the brain, where the sensory input is processed, allowing individuals to detect and differentiate various odors.

Other cranial nerves serve different functions: the optic nerve is involved in vision, the facial nerve controls muscles of facial expression and taste sensations, and the trigeminal nerve is responsible for sensation in the face and motor functions such as biting and chewing. Each of these nerves plays unique roles in sensory and motor functions, highlighting the specialized nature of the cranial nerve system.