Hyoid Arch(redirected from second pharyngeal arch)
Also found in: Dictionary, Medical.
hyoid arch[′hī‚ȯid ‚ärch]
part of the visceral skeleton in vertebrates, including man, located directly behind the maxillary arch. In most cartilaginous fishes, each half of the hyoid arch consists of a superior hyoid cartilage and an inferior hyoid cartilage. Both halves of the hyoid arch unite below in an unpaired element. In bony fishes the superior element of the hyoid arch, which bears the gill cover, is segmented into the suspensorium proper and a connective bone; the hyoid bears rays of the branchiostegal membrane. The unpaired connective element of the hyoid arch is covered with a mucous membrane (the tongue of fishes) and is often equipped with teeth. In most terrestrial vertebrates, including man, the suspensorium is converted into an auditory ossicle known as the stapes, whereas the inferior element becomes part of the hyoid apparatus.