Atlas and abstract of the diseases of the larynx / by L. Grünwald ; authorized translation from the German edited by Charles P. Grayson.

  • Grünwald, L. (Ludwig), 1863-1927.
Date:
1902, ©1898
Catalogue details

Licence: Public Domain Mark

Credit: Atlas and abstract of the diseases of the larynx / by L. Grünwald ; authorized translation from the German edited by Charles P. Grayson. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

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    ages on each other—the intrinsic muscles. It will be best to consider them in connection with their individual actions. The lateral and posterior crico-arytenoid muscles are inserted into tlie outer angle of the base of the arytenoid cartilages; therefore known as the muscular process. The lateral portions arise by a fan-shaped origin from the sides of the arytenoid cartilages externally; the posterior, on the other hand, have their broad origin on the posterior surfice of the same cartilage. The posterior muscles em- brace the posterior and lateral portions of the muscular processes; the lateral muscles only the lateral. As the center of the arytenoid cartilage must form the pivot, the action of these muscles is clear. The lateral crico-aryte- noid muscles draw the muscular process forward and out- ward, so that the vocal process (anterior angle of the base of the arytenoid cartilage) moves inward and backward; the posterior crico-arytenoid nmscles have a directly an- tagonistic action. As the true vocal cords are attached to the vocal process, they necessarily follow these move- ments, and the muscles are therefore known respectively as the adductors and abductors of the true vocal cords. The transverse arytenoid muscle passes transversely across between the two arytenoid cartilages in the middle line, and by its contraction effects mesial approximation of the two cartilages. When these muscles, assisted by the lateral crico-arytcMioid muscles, are put on the stretch they effectually fix the arytenoid cartilages, so that the latter afford a fixed origin to another muscle, the thyro- arytenoid, which again consists of two fasciculi, the infe- rior or internal and superior or external. The inferior thyro-arytenoid muscle lies within the membranous fold known as the true vocal cord (and parallel with it), the suj)eri<)r within the fold known as tlie ventricular band ; botli are inserted into tlie lower half of the thyroid cartil- age at the line of junction of the two alae. The action of the muscles is, therefore, to ])ut these folds on tlie stretch whenever botii their anterior and posterior points of attach-