Pharyngeal groove
Encyclopedia
A pharyngeal groove is the counterpart of the branchial pouch
on the ectoderm
al side.
The first pharyngeal groove produces the external auditory meatus. The rest (2, 3, and 4) are overlapped by the growing 2nd pharyngeal arch, and form the floor of the depression termed the cervical sinus
, which opens ventrally, and is finally obliterated.
Branchial pouch
In the development of vertebrate animals, pharyngeal or branchial pouches form on the endodermal side between the branchial arches, and pharyngeal grooves form the lateral ectodermal surface of the neck region to separate the arches....
on the ectoderm
Ectoderm
The "ectoderm" is one of the three primary germ cell layers in the very early embryo. The other two layers are the mesoderm and endoderm , with the ectoderm as the most exterior layer...
al side.
The first pharyngeal groove produces the external auditory meatus. The rest (2, 3, and 4) are overlapped by the growing 2nd pharyngeal arch, and form the floor of the depression termed the cervical sinus
Cervical sinus
The mandibular and hyoid arches grow more rapidly than those behind them, with the result that the latter become, to a certain extent, telescoped within the former, and a deep depression, the cervical sinus, is formed on either side of the neck....
, which opens ventrally, and is finally obliterated.
External links
- http://isc.temple.edu/marino/embryology/parch98/parch_text.htm