On the physiological action of the muscles concerned in the movements of the lower jaw / by Thomas Brian Gunning.

  • Gunning, Thomas Brian, -1889.
Date:
1868
Catalogue details

Licence: Public Domain Mark

Credit: On the physiological action of the muscles concerned in the movements of the lower jaw / by Thomas Brian Gunning. 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.

    14/28 (page 10)
    lO hyoid aponeurosis. It forms a strong layer of fascia be- tween the anterior portions of the two muscles, and a firm investment for the other muscles of this region. This muscle is peculiar in not being inserted into the hyoid bone, but attached to it by a loop ; this allows the muscle to act without interfering too much with the hyoid bone. The digastric muscle has not, however, that freedom which is attributed to it as a reflected cord, for its aponeurotic connection with the hyoid bone and adjoining muscles prevents it from sliding through the loop which attaches it to the hyoid bone, except to a very limited extent. This powerful muscle exerts great influence from the various and important movements in which it takes part. The service supposed to be rendered by the forego- ing muscles is shown by the following selections: J. Cruveilhier says : The sterno-hyoid, the omo- hyoid^ the sterno-thyroid^ and the thyro-hyoid are the sim- plest in their structure and the simplest in their action ; all cooperate to the lowering of the jaw. Moreover, if the jaw is fixed, they tend to flex the head.* Sappey says that the genio-hyoid raises the hyoid bone when the jaw is fixed, and lowers the jaw when the hyoid bone is fixed, and flexes the head when both are fixed.f J. Cruveilhier says of the digastric: If the hy- oid bone is fixed the posterior belly becomes the lower- er of the jaw, in consequence of the reflection of the * Traite d'Anatomie Descriptive. 3me ed., tome zme, p. 179. f Traite d'Anatomie Descriptive. Tome I, premiere partie, p. 213. Paris. 1850.