A defective model of the chick thymus was created by administering RA, which disrupted the signalling molecular cascade involving endothelin-1, essential for normal development of branchial arches
Miyake & McEachran (1991) worked with the branchial arches
skeleton of batoids, including some Urotrygonids species.
An important step in approaching syndromes of the first and second branchial arches
is identification of defects, including cleft lip with or without cleft palate, micrognathia and atresia of the external auditory canal.
Sakamoto (1984) utilized data on the branchial apparatus in his phylogenetic studies of Pleuronectidae, exploiting seven characters: 5th ceratobranchials, the shape of the 1st epibranchial, teeth on the 3rd epibranchial, gill rakers on the upper limb of the branchial arch, spines on gill rakers, shape of gill rakers and bony plates on the branchial arches
2 There is occasional, associated deformities of soft tissue structures derived from the lower branchial arches
seen in these patients, there may be cleavage of the neck and manubrium sterni.
1) It is postulated that these are developmental lesions derived from remnants of the cartilaginous matrix of the second and third branchial arches
Hemifacial microsomia (HFM) corresponds to a spectrum of congenital craniofacial malformations characterized by hypoplasia of tissues embryologically originating from the first and second branchial arches
Regarding the genus Benthobatis, there is available information on the neurocranium, hyomandibula, branchial arches
, scapulocoracoid, propterygium, synarcual, pelvic girdle and clasper (Carvalho 1999a, Rincon et al.
3,4) The tympanic ring appears first at the embryonic period from mesenchymal tissue lying between the first and second branchial arches
DISCUSSION: Congenital cysts are dysembryogenetic lesions that can occur due to ectodermal elements getting entrapped during midline fusion of mesodermal elements of first and second branchial arches
, between 3rd and 4th weeks of intrauterine life.
They feed, while swimming slowly with their mouths wide-open, allowing water and plankton to pass through the buccal cavity, into the pharynx and across the branchial arches
, which are lined with numerous gill rakers (1260 gill rakers per gill: Bigelow & Schroeder, 1948, p.
Pre-auricular sinus is a congenital malformation that is due to failure of the hillocks of the first and second branchial arches
(which form the auricle) to fuse completely.