Search results
Results from the WOW.Com Content Network
The branchial system is typically used for respiration and/or feeding. Many fish have modified posterior gill arches into pharyngeal jaws, often equipped with specialized pharyngeal teeth for handling particular prey items (long, sharp teeth in carnivorous moray eels compared to broad, crushing teeth in durophagous black carp).
The first pharyngeal arch, also mandibular arch (corresponding to the first branchial arch of fish), is the first of six pharyngeal arches that develops during the fourth week of development. [10] It is located between the stomodeum and the first pharyngeal groove .
The dental arches are the two arches (crescent arrangements) of teeth, one on each jaw, that together constitute the dentition.In humans and many other species, the superior (maxillary or upper) dental arch is a little larger than the inferior (mandibular or lower) arch, so that in the normal condition the teeth in the maxilla (upper jaw) slightly overlap those of the mandible (lower jaw) both ...
It is widely accepted that there is a factor within the tissues of the first branchial arch that is necessary for the development of teeth. [2] The tooth bud (sometimes called the tooth germ) is an aggregation of cells that eventually forms a tooth and is organized into three parts: the enamel organ, the dental papilla and the dental follicle. [3]
Pattern of the branchial arches. I-IV branchial arches, 1–4 pharyngeal pouches (inside) and/or pharyngeal grooves (outside) a Tuberculum laterale b Tuberculum impar c Foramen cecum d Ductus thyreoglossus e Sinus cervicalis
Originally it was the lower of two cartilages which supported the first branchial arch in early fish. Then it grew longer and stronger, and acquired muscles capable of closing the developing jaw. [1] In early fish and in chondrichthyans (cartilaginous fish such as sharks), the Meckelian Cartilage continued to be the main component of the lower jaw.
The tooth germ is an aggregation of cells that eventually forms a tooth. [2] These cells are derived from the ectoderm of the first pharyngeal arch and the ectomesenchyme of the neural crest. [1] [3] [4] The tooth germ is organized into three parts: the enamel organ, the dental papilla and the dental sac or follicle.
If teeth do not start to develop at or near these times, they will not develop at all. A significant amount of research has focused on determining the processes that initiate tooth development. It is widely accepted that there is a factor within the tissues of the first pharyngeal arch that is necessary for the development of teeth. [26]