Vocal Cord Palsy

Anatomy of vagus nerve: The vagus nerve arises from three nuclei located in the medulla of brain. They are (DAT) 1. Nucleus ambiguous (Motor) 2. Nucleus dorsalis 3. Nucleus of tractus solitaries Nucleus ambiguus: Is the motor nucleus of the vagus nerve (upper part give fibres to 9 nerve and lower to 10 th ). The efferent fibers of the dorsal nucleus innervates the involuntary muscles of bronchi, esophagus, heart, stomach, small intestine, and part of the large intestine. The efferent fibers of the nucleus of the tractus solitarius carry sensory fibers from the pharynx, larynx, and esophagus. The vagus nerve (wanderer) takes a tortuous path after emerging from the jugular foramen. It has two ganglions. The smaller superior ganglion and a larger inferior or nodose ganglion. Neck it runs in carotid sheath Supplies most muscles of pharynx and palate. Rt Vagus – 32cm whereas Left is 43cm long. Due to these variations in the length of vagus nerve, there could be a discernible lag in the movement of left vocal cord in comparison with the right cord. To minimize this lag the left recurrent laryngeal nerve is supposed to contain more larger and fast conducting nerve fibers.