The following is an outline for a brief optional lecture (~15 minutes) on cranial and spinal nerves that can be given before students work on the lesson. Instead of using this lecture, consider having students read the appropriate pages in their anatomy textbook before class and hold them accountable using a pre-class quiz (either online or in-class as soon as they arrive).
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Introduction to the peripheral nervous system
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Cranial nerves o Overview of 12 cranial nerves o All originate from brain, nerves III to XII originate from brain stem o Some are motor, some are sensory, some are both o Sensory cell bodies lie in ganglia just outside of brain o Motor cell bodies lie in brain stem nuclei o Cranial nerves must pass through foramina in skull to exit skull o Most cranial nerves serve the face and neck, except for the vagus nerve (X) that plays a major role in parasympathetic innervation to internal viscera
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Spinal nerves o 31 pairs of spinal nerves (31 on each side of the body) o All have both motor and sensory fibers o Somatic sensory cell bodies lie in dorsal root ganglia o Somatic motor cell bodies lie in ventral horn o Nerves to the dorsal side of torso, abdomen, and neck follow through dorsal rami o Nerves to the ventral side of torso, abdomen, and neck, and to all limbs follow through ventral rami o All numbered spinal nerves exit the spinal column inferior to the same numbered vertebrae (e.g. spinal nerve T6 exits the spinal column inferior to vertebrae T6) with the exception of spinal nerve C1, which exits superiorly to vertebrae C1 o The major spinal nerves derive from the nerve plexuses:
 Cervical plexus (phrenic nerve)
 Brachial plexus (ulnar, radial, musculocutaneous, axillary, and median nerves)
 Lumbar plexus (obturator and femoral nerves)
 Sacral plexus (sciatic, common fibular, and tibial nerves) o The named spinal nerves are composed of fibers from two or more numbered spinal nerves that merge together as they pass through the nerve plexuses o Spinal nerves have specific motor and sensory components and may innervate muscle groups that do not overlap with cutaneous areas