A pharyngeal groove (or branchial groove, or pharyngeal cleft
) is made up of ectoderm unlike its counterpart the
pharyngeal pouch on the
endodermal side.
The first pharyngeal groove produces the
external auditory meatus
The ear canal (external acoustic meatus, external auditory meatus, EAM) is a pathway running from the outer ear to the middle ear. The adult human ear canal extends from the pinna to the eardrum and is about in length and in diameter.
Str ...
(ear canal).
The rest (2, 3, and 4) are overlapped by the growing 2nd
pharyngeal arch
The pharyngeal arches, also known as visceral arches'','' are structures seen in the embryonic development of vertebrates that are recognisable precursors for many structures. In fish, the arches are known as the branchial arches, or gill arche ...
, and form the floor of the depression termed the
cervical sinus
The cervical sinus is a structure formed during embryonic development. It is a deep depression found on each side of the neck. It is formed as the second pharyngeal arch (hyoid arch) grows faster than the other pharyngeal arches, so they become ...
, which opens ventrally, and is finally obliterated.
See also
*
Branchial cleft cyst
References
Animal developmental biology
Pharyngeal arches
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