The document discusses three medical cases: 1. Guillain-Barre Syndrome, including the anatomy and histology of peripheral nerves, neuromuscular junction, myelination, classifications of nerve fibers, and peripheral nerve disorders. 2. Spinal injury and PTSD, covering anatomy of the vertebrae and spinal cord, spinal cord injuries, ascending and descending tracts, reflex arcs, spinal cord diseases, and the diagnostic criteria for PTSD. 3. Parkinson's Disease, addressing the anatomy and neurotransmitters related to movement, definitions and classifications of parkinsonism, the pathology and pathophysiology of PD, clinical features and management of PD.