The document discusses the peripheral nervous system, including: 1. Sensory receptors and motor endings in the extremities, as well as the cranial nerves and four main plexuses. 2. Reflexes require stimulus, sensory information, central processing, motor activation, and a peripheral response. 3. Peripheral sensory receptors include free nerve endings and encapsulated endings that detect stimuli like touch, pressure, and proprioception. 4. Motor endings similarly to synapses activate skeletal muscle, smooth muscle and glands. 5. Cranial nerves originate and terminate in specific brain regions, carrying sensory and motor fibers.