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

(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.

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

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]
References in periodicals archive ?
In our opinion, the principal observation that requires explanation is the distribution and orientation of the putative chemosensory neurons relative to the shape of the surrounding ectoderm in which they reside.
BMP2/4a is expressed at lower levels throughout the non-neural ectoderm at E4, with more prominent expression at the border between the neural and non-neural ectoderm, highly reminiscent of that reported in Xenopus and zebrafish.
Immunoreactive processes located in what appeared to be the base of the ectoderm covered the entire tentacle (Fig.
This expansion was caused by thinning of the ectoderm (Fig.
Interradial ridges of ectoderm (associated with the left dorsal bulge, left ventral bulge, posterior lobe, right ventral bulge, and preoral lobe) are positioned near the developing juvenile mouth.
The lens is derived from the surface ectoderm. Similarly, lens formation begins in the third week of gestation as the "lens placode" and initial development concludes in the seventh week.
To create an organoid, they used a cocktail of chemicals that allowed the formation of the oral ectoderm. The cocktail induced the embryonic stem cells to form the ectoderm; viral vectors then got the cells to express both Sox9 and Foxc1.
They are postulated to originate from the congenital inclusion of ectoderm and mesoderm layers lined by stratified epithelium covered by laminated keratin material containing adnexal structures of the skin such as hair follicles, sebaceous and sweat glands, smooth muscle, and fibro-adipose tissue.
Skin develops from the germ layer ectoderm and brain develops from the same ectoderm.
Sox3 is important regulator for the neurogenic capacity of surface ectoderm and regulates the ability of the ectoderm to undergo neurogenesis (Tripathi et al., 2009).