Vagal trigone

Part of the brainstem associated with the vagus nerve

Vagal trigone

The vagal trigone is a small, triangular area located in the floor of the fourth ventricle of the brainstem. It is associated with the vagus nerve (cranial nerve X) and is part of the medulla oblongata.

Anatomy

The vagal trigone is situated in the caudal portion of the rhomboid fossa, which forms the floor of the fourth ventricle. It is located lateral to the hypoglossal trigone, which is associated with the hypoglossal nerve (cranial nerve XII). The vagal trigone overlies the dorsal motor nucleus of the vagus nerve, which is responsible for parasympathetic innervation to various organs.

Function

The dorsal motor nucleus of the vagus nerve, located beneath the vagal trigone, plays a crucial role in autonomic control. It provides parasympathetic innervation to the heart, lungs, and digestive tract, influencing heart rate, respiratory rate, and gastrointestinal motility.

Clinical significance

Lesions affecting the vagal trigone or the underlying dorsal motor nucleus can lead to dysfunctions in the autonomic control of the organs innervated by the vagus nerve. This can result in symptoms such as bradycardia, dysphagia, and gastrointestinal disturbances.

Images

Diagram of the floor of the fourth ventricle. The vagal trigone is labeled at the lower right.

Posterior view of the human caudal brainstem, showing the location of the vagal trigone.

Related pages

• Vagus nerve
• Medulla oblongata
• Fourth ventricle

References

• Standring, S. (2020). Gray's Anatomy: The Anatomical Basis of Clinical Practice. 42nd edition. Elsevier.
• Purves, D., Augustine, G. J., Fitzpatrick, D., et al. (2018). Neuroscience. 6th edition. Oxford University Press.

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  Vagal trigone
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  Vagal trigone