The Efferent System of Cranial Nerve Nuclei: A Comparative Neuromorphological Study

1 Introduction.- 1.1 Theories Regarding the Evolution of the Head.- 1.2 The Classification of Cranial Nerves.- 1.3 Inconsistencies and Contradictions in the Classification of Cranial Nerves.- 2 Materials and Methods.- 3 The Hypoglossal Nucleus: The Appearance of the Muscular Tongue.- 3.1 Frog.- 3.2 Lizard.- 3.3 Rat.- 3.4 Conclusion.- 4 The Control of Patterned Eye Movements: The Oculomotor, Trochlear, and Abducens Nuclei.- 4.1 The Positions of the Eye Moving Nuclei and the Organization of Muscle Innervation.- 4.2 Neuronal Morphology in the Eye Moving Nuclei.- 4.3 Conclusion.- 5 The Protection of the Eye: The Accessory Abducens Nucleus.- 5.1 The Position of the Accessory Abducens Nucleus.- 5.2 The Neuronal Morphology in the Accessory Abducens Nucleus.- 5.3 The Function of the Accessorius Abducens-Retractor Bulbi System.- 5.4 Conclusion.- 6 Control of Jaw Movements and Facial Expression: The Trigeminal and Facial Nuclei.- 6.1 The Primary Mandibular Joint and Its Muscles.- 6.2 The Secondary Mandibular Joint and Its Muscles.- 6.3 The Control of Movements at the Primary Mandibular Joint: The Amphibian and Sauropsidian Trigeminal and Facial Nuclei.- 6.4 The Control of Movement at the Secondary Mandibular Joint: The Mammalian Trigeminal Nucleus.- 6.5 The Control of Facial Expression: The Mammalian Facial Nucleus.- 6.6 Conclusion.- 7 The Muscles of the Middle Ear.- 7.1 The Central Innervation of the Tensor Tympani.- 7.2 The Central Innervation of the Stapedius.- 7.3 Conclusion.- 8 Deglutition and Phonation: The Ambiguus Nucleus.- 8.1 The Innervated Periphery.- 8.2 The Structure and Cytoarchitecture of the Ambiguus Nucleus.- 8.3 Conclusion.- 9 The Control of Head Movements: The Accessory Nerve Nucleus.- 9.1 The Periphery.- 9.2 The Accessory Nerve.- 9.3 The Topography and Cytoarchitecture of the Accessory Nerve Nucleus.- 10 Neurons of the Cranial Parasympathetic Outflow.- 10.1 The Edinger-Westphal Nucleus and Ciliary Ganglion System.- 10.2 The Medullary Parasympathetic Outflow.- 10.3 Conclusion.- 11 General Conclusions.- 11.1 The Arrangement of Cranial Nerve Motor Nuclei.- 11.2 Comments on the Morphological Classification.- 11.3 Trends in the Evolution of Cranial Nerve Nuclei.- 11.4 Corollary Considerations.- 11.5 Summary.- References.