Ectoderm is one of the three primary germ cell  layers in the very early embryo.  with the 
ectoderm as the most exterior (or distal) layer
Kaynak: Ectoderm Animals with radial symmetry , like cnidaria ns, produce two germ layers (the 
ectoderm  and endoderm ) making them diploblastic .
Kaynak: Germ layerThe surface 
ectoderm (or external 
ectoderm) forms the following structures: Skin  (only epidermis; dermis is derived from mesoderm) (along
Kaynak: Surface ectodermThe other two layers are the 
ectoderm  (outside layer) and mesoderm  (middle layer), with the endoderm as the innermost layer Cells
Kaynak: EndodermIn Xenopus laevis , the specification of the three germ layers (endoderm , mesoderm  and 
ectoderm ) occurs at the blastula  stage Great
Kaynak: Ectoderm specificationThese three germ layers  are known as the 
ectoderm , mesoderm , and endoderm  Gastrulation takes place after cleavage  and the formation of
Kaynak: GastrulationNeuroectoderm (or neural 
ectoderm or neural tube epithelium) is the term for 
ectoderm  which receives Bone Morphogenetic Protein -
Kaynak: NeuroectodermThe other two layers are the 
ectoderm  (outside layer) and endoderm  (inside layer), with the mesoderm as the middle layer between them
Kaynak: MesodermThe stomodeum is lined by 
ectoderm , and is separated from the anterior end of the fore-gut  by the buccopharyngeal membrane.
Kaynak: StomodeumThe epiblast, whilst referred to as the primary 
ectoderm, differentiates to form all three layers of the trilaminar germ disc  in a
Kaynak: Epiblastenteric neuron s and glia  After gastrulation , neural crest cells are specified at the border of the neural plate and the non-neural 
ectoderm .
Kaynak: Neural crestDiploblasty is a condition of the blastula  in which there are two primary germ layer s: the 
ectoderm  and endoderm .  Diploblastic
Kaynak: DiploblastyBMP is initially secreted from the overlying 
ectoderm.  A secondary signaling center is then established in the roof plate, the dorsal most
Kaynak: Neural tubeThe cyst develops out of 
ectoderm al tissue. Histologically , it is made of a thin layer of squamous epithelium .  Terminology
Kaynak: Epidermoid cystTriploblasty is a condition of the blastula  in which there are three primary germ layer s: the 
ectoderm , mesoderm , and endoderm .
Kaynak: TriploblastyIn embryology , the otic placode is a thickening of the 
ectoderm  on the outer surface of a developing embryo  from which the ear
Kaynak: Otic placodeA neurogenic placode is an area of thickening of the epithelium  in the embryo nic head 
ectoderm  layer that gives rise to neurons and
Kaynak: Neurogenic placodesIn front of the primitive streak  two longitudinal ridges, caused by a folding up of the 
ectoderm, make their appearance, one on either
Kaynak: Neural foldThe region where the crescentic masses of the 
ectoderm  and endoderm  come into direct contact with each other constitutes a thin
Kaynak: Buccopharyngeal membraneDuring the third week of embryonic development , two areas of thickened 
ectoderm , the olfactory areas, appear immediately under the
Kaynak: Frontonasal prominence