The Vagus Nerve (Cranial Nerve X)

The vagus nerve is partially responsible for parasympathetic control of the heart, lungs, and digestive tract[1]. The parasympathetic nervous system is more commonly referred to as the “rest and digest” state of the body. This is on contrast to the sympathetic nervous system, which is responsible for the “fight or flight” state of the body[2]. The vagus nerve leaves the medulla oblongata and travels down the neck, chest, and finally the abdomen[1]. It comprises 80% to 90% of afferent nerves containing mainly sensory information about the body’s organs to the central nervous system (CNS)[3]. The vagus nerve doubles as a sensory and motor nerve.

A few responsibilities of the vagus nerve include controlling heart rate, sweating, movement of muscles in the mouth, including speech, and satiation following food consumption[3].


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  3. Dutschmann, Mathias; Bautista, Tara G.; Mörschel, Michael; Dick, Thomas E. (2014). "Learning to breathe: Habituation of Hering–Breuer inflation reflex emerges with postnatal brainstem maturation". Respiratory Physiology & Neurobiology. 195: 44–49. doi:10.1016/j.resp.2014.02.009. ISSN 1569-9048. PMC 4111629. PMID 24566392.