Part I. Human Peripheral Nerve -- 1. Ultrastructure of Myelinated and Unmyelinated Axons -- 2. Macrophages, Mastocytes, and Plasma Cells -- 3. Ultrastructure of the Endoneurium -- 4. Ultrastructure of the Perineurium -- 5. Ultrastructure of the Epineurium -- 6. Origin of the Fascicles and Intraneural Plexus -- 7. Macroscopic View of the Cervical Plexus and Brachial Plexus -- 8. Anna Carrera, Francisco Reina -- 9. Macroscopic View of the Lumbar Plexus and Sacral Plexus -- 10. Cross-sectional Microscopic Anatomy of the Sciatic Nerve and its Dissected Branches -- 11. Cross-sectional Microscopic Anatomy of the Sciatic Nerve and Paraneural Sheaths -- 12. Computerized Tomographic Images of Unintentional Intraneural Injection -- 13. Ultrasound View of Unintentional Intraneural Injection -- 14. Histologic Features of Needle-Nerve and Intraneural Injection Injury as Seen on Light Microscopy -- 15. Structure of Nerve Lesions after "In Vitro" Punctures -- 16. Scanning Electron Microscopy View of In Vitro Intraneural Injections -- 17. Injection of Dye Inside the Paraneural Sheath of the Sciatic Nerve in the Popliteal Fossa -- 18. High-Definition and Three-Dimensional Volumetric Ultrasound Imaging of the Sciatic Nerve -- Part II. Component of the Spinal Canal -- 19. Spinal Dural Sac, Nerve Root Cuffs, Rootlets, and Nerve Roots -- 20. Ultrastructure of Spinal Dura Mater -- 21. Ultrastructure of the Spinal Arachnoid Layer -- 22. Three-Dimensional Reconstruction of Spinal Dural Sac -- 23. Three-dimensional Reconstruction of Spinal Epidural Fat -- 24. Ultrastructure of Human Spinal Trabecular Arachnoid -- 25. Ultrastructure of Spinal Pia Mater -- 26. Ultrastructure of Spinal Subdural Compartment: Origin of Spinal Subdural Space -- 27. Unintentional Subdural and Intradural Placement of Epidural Catheters -- 28. Ultrastructure of Human Spinal Nerve Roots -- 29. Three-dimensional Reconstruction of Cauda Equine Nerve Roots -- 30. Spinal  Nerve Root Lesions after "In Vitro" Needle Puncture -- 31. Nerve Root Cuff Lesions after "In Vitro" Needle Puncture and Model of "In Vitro" Nerve Stimuli Caused by Epidural Catheters -- 32. Ligamentum Flavum and Related Spinal Ligaments -- 33. The Ligamentum Flavum -- 34. Subarachnoid (Intrathecal) Ligaments -- 35. Displacement of the Nerve Roots of Cauda Equina in Different Positions -- 36. Nerve Root and Types of Needles Used in Transforaminal Injections -- 37. Three-Dimensional Visualization of Spinal Cerebrospinal Fluid and Cauda Equina Nerve Roots, and Estimation of a Related Vulnerability Ratio -- 38. Ultrastructure of Nerve Root Cuffs: Dura-Epineurium Transition Tissue -- 39. Ultrastructure of Nerve Root Cuffs: Arachnoid Layer-Perineurium Transition Tissue at Preganglionic, Ganglionic, and Postganglionic Levels -- 40. Spinal Cord Stimulation -- 41. Ultrastructure of Dural Lesions Produced in Lumbar Punctures -- 42. Injections of Particulate Steroids for Nerve Root Blockade: Ultrastructural Examination of Complicating Factors -- 43. Nerve Root and Types of Needles Used in Transforaminal Injections -- Part III. Materials -- 44. Needles in Regional Anesthesia -- 45. Catheters in Regional Anesthesia -- 46. Epidural Filters and Particles from Surgical Gloves -- Part IV. Research Techniques -- 47. Three-dimensional Reconstruction of Spinal Cerebrospinal Fluid, Roots, and Surrounding Structures -- 48. Cerebrospinal Fluid and Root Volume Quantification from Magnetic Resonance Images -- 49. Scanning Electron Microscopy -- 50. Transmission Electron Microscopy. .