Search results
Results from the WOW.Com Content Network
The third pouch possesses dorsal and ventral wings. Derivatives of the dorsal wings include the inferior parathyroid glands, while the ventral wings fuse to form the cytoreticular cells of the thymus. The main nerve supply to the derivatives of this pouch is cranial nerve IX, glossopharyngeal nerve.
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 .
Pattern of the pharyngeal arches. I-IV pharyngeal 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. The pharyngeal apparatus is an embryological structure. [1] [2] It consists of: pharyngeal grooves (from ectoderm)
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).
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), Meckel's cartilage continued to be the main component of the lower jaw.
Pharyngeal slits are repeated openings that appear along the pharynx caudal to the mouth. With this position, they allow for the movement of water in the mouth and out the pharyngeal slits. It is postulated that this is how pharyngeal slits first assisted in filter-feeding, and later, with the addition of gills along their walls, aided in ...
The cervical sinus is bounded in front by the second pharyngeal arch (hyoid arch), and behind by the thoracic wall. The second pharyngeal arch (hyoid arch) grows faster than the other pharyngeal arches, so they become covered. It is ultimately obliterated by the fusion of its walls by the 7th week of gestation.
A pharyngeal groove (or branchial groove, or pharyngeal cleft [1]) is made up of ectoderm unlike its counterpart the pharyngeal pouch on the endodermal side. The first pharyngeal groove produces the external auditory meatus (ear canal). [ 2 ]