Lectures on the physical examination of the mouth and throat : with an appendix of cases / by G.V. Poore.

  • Poore, George Vivian, 1843-1904.
Date:
1881
Catalogue details

Licence: Public Domain Mark

Credit: Lectures on the physical examination of the mouth and throat : with an appendix of cases / by G.V. Poore. Source: Wellcome Collection.

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    of the cricoid to the outer angle of the arytenoids, and cause the arytenoid cartilages to rotate inwards. These muscles are adductors, antagonists of the posterior crico-arytenoids, and help to close the glottis. 5. The thyro-arytenoid muscles run parallel to the vocal cords from the thyroid to the arytenoid cartilages, and tend to relax the vocal cords. 6. The muscular fibres covered by the aryteno-epiglottie folds of mucous membrane help to close the glottis and depress the epiglottis, and the thyro-epiglottic muscle also tends to depress the epiglottis. These muscles are all supplied by branches of the vagus, the crico-thyroid by the superior laryngeal, and all the others by the recurrent laryngeal. Now, since the great cause of paralysis is a lesion involving the origin or trunk of a nerve supplying a muscle, it is necessary in considering the para- lyses of the larynx to bear in mind the origin and course of the vagus and its laryngeal branches. The vagi having their deep origins in a grey nucleus at the lower part of the floor of the fourth ventricle, start from the lateral tract of the medulla, and, being joined by fibres from the glosso-pharyngeal and spinal accessory,pass through the jugular foramen, and down the neck within the sheath of the carotid vessels lying between the internal jugular vein and the internal and common carotid arteries as far as the root of the neck. The right nerve crosses the sub- clavian artery between it and the subclavian vein, while the left, lying between the left carotid and subclavian arteries and behind the left innominate vein, crosses in front of the arch of the aorta. The right recurrent laryngeal nerve arises in front of the subclavian artery, winds from before back around the subclavian, and ascends obliquely to the side of the trachea behind the common carotid and inferior thyroid arteries. The left recurrent laryngeal nerve arises in front of the arch of the aorta, and winds from before back around the aorta, close to the junction of the transverse and descending portions of the arch, and just beyond the junction with it of the obliterated ductus arteriosus, and then ascends to the side of the trachea. Both nerves ascend in the groove between the trachea and oesophagus, and enter the larynx behind the articulation of the inferior cornu of the thyroid cartilage with the cricoid. It is a matter of great clinical importance to bear in mind how the course of the vagi in the neighbourhood of the origin of the recurrent laryngeal nerve differs on the two sides. The left recurrent has its origin, so to say, much