The recurrent laryngeal nerves are the nerves of the sixth pharyngeal arch. In the pharynx, the pharyngeal glands secrete mucus. Phonologically, Egyptian contrasted labial, alveolar, palatal, velar, uvular, pharyngeal, and glottal consonants. The facial muscles are derived from the second branchial/pharyngeal arch. The external auditory meatus develops from the dorsal portion of the first pharyngeal cleft. The epiglottis arises from the fourth pharyngeal arch. Thus, uvular, pharyngeal, and glottal fricatives never contrast with approximants. Parafollicular cells are derived from pharyngeal endoderm. The innervation of the esophagus develops from the pharyngeal arches. The skeletal elements and muscles are derived from mesoderm of the pharyngeal arches. Cardiac neural crest develops into melanocytes, cartilage, connective tissue and neurons of some pharyngeal arches. Heth originally represented a voiceless fricative, either pharyngeal , or velar . The tensor tympani muscle develops from mesodermal tissue in the 1st pharyngeal arch. The pulmonary arteries originate from the truncus arteriosus and the sixth pharyngeal arch. It is innervated by the pharyngeal plexus.