*The Vagus Nerve: Anatomical Pathways, Neurovisceral Integration, and Therapeutic Implications*

This paper provides an anatomical and functional exploration of the vagus nerve, CN X, the longest cranial nerve and the principal component of the parasympathetic nervous system. It traces the nerve’s “wandering” pathway from the medulla oblongata through the neck, thorax, and abdomen to the splenic flexure, with distal hindgut supply from the pelvic splanchnic nerves. The review emphasizes the vagus nerve’s dual role: as a predominantly afferent sensory monitor of visceral status, and as an efferent regulator of cardiovascular, gastrointestinal, and immune function. Key focus areas include its central role in the gut-brain axis, its contribution to the comorbidity between functional GI disorders and mood disorders, and its mediation of the cholinergic anti-inflammatory pathway. The paper also examines modern clinical applications, including invasive and transcutaneous vagus nerve stimulation for epilepsy,٧ depression, migraine, and chronic inflammatory diseases. Overall, this work highlights the vagus nerve as a critical neurovisceral interface connecting body, mind, and immunity, and as a promising target for future neuromodulatory therapies.