Action of the pterygoideus muscle during feeding in the lizard Uromastix aegyptius (Agamidae)
Version of Record online: 26 JAN 2005
Copyright © 1978 Wiley-Liss, Inc.
The Anatomical Record
Volume 190, Issue 2, pages 217–222, February 1978
How to Cite
Throckmorton, G. S. (1978), Action of the pterygoideus muscle during feeding in the lizard Uromastix aegyptius (Agamidae). Anat. Rec., 190: 217–222. doi: 10.1002/ar.1091900205
- Issue online: 26 JAN 2005
- Version of Record online: 26 JAN 2005
- Manuscript Accepted: 15 AUG 1977
- Manuscript Received: 7 JUN 1977
The actions of the deep and superficial portions of the ptery-goideus muscle and the depressor mandibulae were studied in the agamid lizard, Uromastix aegyptius, using fine wire electrodes. The EMG signals were recorded, while simultaneously recording the jaw positions during feeding on movie film at 32 fps. Muscle activity varies with different types of food. The deep and superficial portions of the pterygoideus performed different functions. The deep ptery-goideus functioned during opening of the jaws, presumably to protract the jaw. The superficial pterygoideus was strictly a jaw elevator. The depressor mandibu-lae is not the initiator of jaw opening. When biting on tough food items, the deep pterygoideus and depressor mandibular were active.