Hyoid Apparatus


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Hyoid Apparatus

 

part of the visceral skeleton of terrestrial vertebrates, including man, located under the tongue between the branches of the lower jaw.

The hyoid apparatus is a vestige of the gill arches of crossopterygians, which changed in the process of vertebrate evolution. It is most highly developed in apodals and the larvae of caudate amphibians. In these animals the lower section of the hyoid arch and three or four gill arches are clearly distinguishable. In acaudate amphibians all these elements merge into a broad cartilaginous plate bearing four pairs of appendages. In reptiles and birds, the unpaired elements of the gill apparatus form the elongate body of the hyoid apparatus, which serves as support for the tongue; the paired elements form no more than three pairs of appendages, or cornua (also known as horns).

In mammals, including man, the hyoid apparatus is usually called the hyoid bone, which consists of an unpaired body and two pairs of appendages—the major and minor horns. The hyoid bone is fastened by a series of neck muscles, which connect it with the lower jaw and skull and with the clavicles and sternum. In many animals it is also connected with the scapula. The muscles of the tongue also derive from the hyoid bone. The activity of these muscles causes movement of the hyoid bone, the floor of the oral cavity, the tongue, and larynx. The muscles play a large role in swallowing and sound production.

References in periodicals archive ?
(a) Computed tomography, 3-dimensional reconstruction of the hyoid apparatus of the juvenile gyrfalcon described in Figure 1 showing luxation of the right epibranchial bone, (b) Illustration of the hyoid apparatus and luxated right epibranchial bone (Courtesy Dr L.
The microstructure of the hyoid apparatus is shown in Fig.
To examine the role of the hyoid apparatus on dissipating shock energy, the model was subjected to a stress wave impact.
Two factors resulted in a remarkable decrease impulse while the stress wave traveled along the hyoid apparatus. One factor is the thinning structure, and another factor is curvature of the hyoid apparatus.
The unique structure of the hyoid apparatus allows the woodpecker to catch insects from holes of trees.
Differential diagnoses considered for the observed submandibular lingual entrapment were a skeletal abnormality of the hyoid apparatus (including luxation or fracture) or a muscular or a neurologic dysfunction.
Multiple orthogonal and oblique radiographs of the skull and ventrodorsal and right lateral whole body radiographs were obtained with the goose sedated with midazolam (0.7 mg/kg IM) and butorphanol (Torbugesic, Fort Dodge Laboratories Inc, Madison NJ, USA; 0.7 mg/kg IM), revealing soft-tissue distension in the intermandibular sublingual region with ventral displacement of the hyoid apparatus (Fig 2).
A computed tomography scan was performed the next day to elucidate the abnormal position of the tongue and hyoid apparatus. The bird was premedicated with midazolam (0.7 mg/kg IM) and butorphanol (0.7 mg/kg IM) for intravenous catheter placement.