Diseases of the larynx / by J. Gottstein ; translated and added to by P. M'Bride.

  • Gottstein, Jacob, 1832-1895.
Date:
[1885?]
Catalogue details

Licence: Public Domain Mark

Credit: Diseases of the larynx / by J. Gottstein ; translated and added to by P. M'Bride. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    ANATOMY OF THE LARYNX. thyroid cartilage, at about the middle of its receding angle (anterior commissure). The fibres only unite to form a cord anteriorly, then divide into separate groups, of which one passes along the free edge and becomes attached to the point of the processus vocalis; a second lies on the upper surface of the cord, and is inserted immediately behind the posterior extremity of the ventricle; while a third is situated on the under surface of the cord, and is attached below the processus vocalis to the median surface of the arytenoid cartilage, or the anterior surface of the cricoid jilate. In addition to elastic fibrous tissue, the substance of the vocal cords is to a great extent composed of the fibres of the internal thyro-arytenoid muscle. On making a section, one sees that its shape is triangular or prismatic. Two sides of the triangle are free, of which one is directed upwards towards the ventricular band, the other is directed downwards and inwards towards the lower part of the opposing wall of the trachea, while the third surface represents the outer attachment. Besides the true there also occur false ligaments, which are onl}'^ formed by reduplications of the mucous membrane. As the latter passes from the base of the tongue to the upper surface of the epiglottis there are produced, besides the median fold, Avhich has been already referred to,, and in Avhich the median giosso-epigiottic ligament is coiicealed, also two lateral folds (lateral glosso-epiglottic folds), so that two shallow depressions are formed on each side. The mucous membrane descends from the lateral wall of the pharynx over the inner surface of the thyroid cartilage, and then again ascends, and in this way the aryepi- glottic folds or ligaments are formed. The depression Avhich is thus produced on either side is spoken of as the sinus pyriformis. The muscles of the larynx may be divided, according to their physio- logical function, into two groups; the first embraces those which move the larynx as a whole, whether it be to raise, lower, or fix it; the second, those which change the position of the cartilages relative to one another, and in this way regulate the shape of the organ and the tension of its elastic portions, more especially the A^ocal cords. The muscles of the second group may be divided as follows : (1) Those whose function it is to maintain a way of communication between the external atmosphere, the respiratory muscles proper, and the lungs; (2) those which produce closure of the glottis requisite for phonation, and also render possible absolute closure when it is desired to place the air within the lungs \uider great pressure, and to continue this pressure; (3) those which regulate the tension of the vocal cords. Among those muscles whose fimction it is to fix the larynx and to raise and lower it, we number the storno-thyroid, which draws down the larynx; the thyro-hyoid, which raises it as a whole; and, finally, the inferior constrictor of the pharynx, which either, like the preceding,