Cranial nerves are nerves of the PNS that originate from or terminate in the brain. There are 12 pairs of cranial nerves, all of which pass through foramina of the skull. Some cranial nerves are sensory nerves (containing only sensory fibers), some are motor nerves (containing only motor fibers), and some are mixed nerves (containing a combination of sensory and motor nerves). Characteristics of the cranial nerves, which are numbered from anterior to posterior as they attach to the brain, are summarized in Table 1.