ectoderm


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Related to ectoderm: mesoderm

ectoderm

 [ek´to-derm]
the outermost of the three primary germ layers of the embryo; from it are derived the epidermis and epidermic tissues such as nails, hair, and glands of the skin; the nervous system; external sense organs such as the eye and ear; and the mucous membranes of the mouth and anus. adj., adj ectoder´mal, ectoder´mic.

ec·to·derm

(ek'tō-dĕrm),
The outer layer of cells in the embryo, after establishment of the three primary germ layers (ectoderm, mesoderm, endoderm), the germ layer in contact with the amnionic cavity.
Synonym(s): ectoblast (1)
[ecto- + G. derma, skin]

ectoderm

/ec·to·derm/ (ek´to-derm) the outermost of the three primitive germ layers of the embryo; from it are derived the epidermis and epidermic tissues, such as the nails, hair, and glands of the skin, the nervous system, external sense organs and mucous membrane of the mouth and anus.ectoder´malectoder´mic

ectoderm

(ĕk′tə-dûrm′)
n.
1. The outermost of the three primary germ layers of an embryo, from which the epidermis, nervous tissue, and, in vertebrates, sense organs develop.
2. The outer layer of a diploblastic animal, such as a jellyfish.

ec′to·der′mal, ec′to·der′mic adj.

ectoderm

[ek′tədurm]
Etymology: Gk, ektos, outside, derma, skin
the outermost of the three primary cell layers of an embryo. The ectoderm gives rise to the nervous system; the organs of special sense, such as the eyes and ears; the epidermis and epidermal tissue, such as fingernails, hair, and skin glands; and the mucous membranes of the mouth and anus. See also embryo, endoderm, mesoderm. ectodermal, ectodermic, adj.

ec·to·derm

(ek'tō-dĕrm)
The outer layer of cells in the embryo, after establishment of the three primary germ layers (e.g., ectoderm, mesoderm, endoderm).
Synonym(s): ectoblast (1) .
[ecto- + G. derma, skin]

ectoderm

The outermost of the three primary germ layers of an embryo, the others being the MESODERM and the ENDODERM. The ectoderm develops into the skin, the nervous system, and the sense organs.

ectoderm

or

ectoblast

the germ layer lying on the outside of the developing embryo that eventually gives rise largely to the EPIDERMIS, but also to nervous tissue and, where present, nephridia (see NEPHRIDIUM). Compare ENDODERM.

ectoderm

primary germ layer of embryonic cells, forming epidermal structures and nerve tissue

ectoderm

The outermost of the three primary germinal layers of an embryo (the other layers being mesoderm and endoderm) from which the eye is derived. It differentiates into outer surface ectoderm and inner neuroectoderm, which gives rise to neural crest cells. The surface ectoderm gives rise to the crystalline lens, the lacrimal gland, the meibomian glands, the corneal and conjunctival epithelium and the epidermis of the eyelids. The neuroectoderm (neural ectoderm) will form the retina, retinal pigment epithelium, the pigmented and non-pigmented layers of the ciliary and iris epithelium, the dilator and sphincter muscles of the iris and the optic nerve fibres. Neural crest cells will form the corneal stroma and endothelium, sclera, iris and choroidal stroma, ciliary muscle and trabecular meshwork. See optic cup; mesoderm; optic vesicles.

ec·to·derm

(ek'tō-dĕrm)
Outer layer of cells in the embryo, after establishment of the three primary germ layers (ectoderm, mesoderm, endoderm).
[ecto- + G. derma, skin]

ectoderm

(ek´tədurm),
n the outermost of the three primary cell layers of an embryo. The ectoderm gives rise to the nervous system, the organs of special sense, the epidermis, and epidermal tissues such as fingernails, hair, and skin glands.

ectoderm

the outermost of the three primitive germ layers of the embryo; from it are derived the epidermis and epidermal derivatives, such as the claws, hair and glands of the skin, the nervous system, external sense organs (eye, ear, etc.) and mucous membrane of the mouth and anus.
References in periodicals archive ?
There is international research providing evidence of proliferation activity in both the mesenchyme and ectoderm of the developing limbs in human embryos (4th-8th week old) using electron microscope and immunohistochemistry.
The beginning of each treatment should be concerned with the balancing of the embryonic germinal tissue layers such as the ectoderm, mesoderm, and endoderm, speaking of the colon and internal organs.
2D, arrowheads); neither the ectoderm nor cells of the gastroderm reacted for phenoloxidase.
It is known that the mandibular tissue derived from the neural crest, which in turn interacts with tissue as the endoderm and ectoderm result in the formation of this structure and the BMPs in turn play a key role as a regulator of development of neural crest cells and their derivatives.
The double knockout of Dlx5 and Dlx6 (Dlx5/6 D-KO) in the mice causes ectrodactyly in the hind limbs with defective development of the middle portion of the apical ectoderm ridge (AER)23,24.
The proximo-distal sequence of origin of parts of the chick wing and on the role of the ectoderm.
Wnt-7a is expressed in the dorsal ectoderm and upregulates the production of LIM homeobox transcription factor 1, alpha (Lmx-1), which in turn causes dorsal differentiation of the limb.
Breast tissue is modification of sweat glands and is derived from downward migration of ectoderm into the underlying mesenchyme.
The so-called KID (keratitis, ichthyosis, deafness) syndrome is a congenital disorder of ectoderm that affects not only the epidermis, but also other ectodermal tissues such as the corneal epithelium and the inner ear.
The histopathological examination revealed that the tumor included structures derived from all 3 germ cell layers: ectoderm, mesoderm, and endoderm (eg, cartilaginous, osseous, hematopoietic, fibrous, nervous, glandular, squamous epithelial, and smooth muscle tissues).
The pathogenesis of encephalocele may be explained by separation of surface ectoderm and neuro-ectoderm in the midline just after closure of neural fold.
The development is related to incomplete separation of the notochord from the embryonic foregut or herniation of the endoderm of the embryonic foregut into the dorsal ectoderm.