QS Study

The vagus nerve is the longest cranial nerve. It is a functionally diverse nerve, offering many different modalities of innervation. It contains motor and sensory fibers and, because it passes through the neck and thorax to the abdomen, has the widest distribution in the body.

Functional components of vagus nerve –

  • Special visceral efferent fibers.
  • General visceral efferent fibers.
  • General visceral afferent fibers.
  • Special visceral afferent fibers.
  • General somatic afferent fibers.

Due to its widespread functions, pathology of the vagus nerve is implicated in a vast variety of clinical cases.

vagus nerve 1

Fig: Functional Components of Vagus Nerve

Distribution in abdomen

The right and left vagus nerve enter the abdomen through the oesophageal opening of the diaphragm. In the abdomen, the vagal trunks terminate by dividing into branches that supply the oesophagus, stomach and the small and large bowl.

The posterior vagal trunk (right vagus nerve)

vagus nerve 2

Fig: Distribution in an abdomen of Vagus Nerve

The anterior vagal trunk (left vagus nerve)

It divides into several branches which supply the:

  • Stomach.
  • Liver.
  • The upper part of the duodenum.
  • Head of the pancreas.
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