[Morphodifferentiation of the stapedius muscle. Personal contribution]

The aim of this study is to explain the origin of the anomalies and variations that affect the muscle-tendon complex of the stapes. These are interpreted from the model of the stapes muscle differentiation formed by two independent anlagen (Rodríguez-Vázquez, 2005, 2009 and Rodríguez-Vázquez et al., 2010): one for the belly muscle, located on the second branchial arch medially to the facial nerve; and another for the tendon, formed from the internal segment of interhiale. The external segment of the interhiale usually disappears. The pyramidal eminence is organized from the mesenchymal condensation sorrounding the muscle belly, which is independent of the second branchial arch cartilage.