germ layer

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layer

 [la´er]
a thin, flat plate or stratum of a composite structure; called also lamina.
ameloblastic layer the inner layer of cells of the enamel organ, which forms the enamel prisms of the teeth.
abrasion layer a protective covering of gelatin enclosing an emulsion on x-ray film; called also overcoat.
bacillary layer layer of rods and cones.
basal layer of endometrium the deepest layer of the uterine endometrium; it provides the regenerative endometrium after menstrual loss of the functional layer.
basal layer of epidermis stratum basale.
blastodermic layer germ layer.
clear layer stratum lucidum.
columnar layer mantle layer.
compact layer of endometrium a sublayer of the functional layer of endometrium, which faces the lumen of the uterus and contains the necks of the uterine glands.
enamel layer the outermost layer of cells of the enamel organ.
functional layer of endometrium the layer of endometrium facing the lumen of the uterus; its cells are cast off at menstruation and childbirth. Sublayers are the compact layer and the spongy layer. It is known as the decidua during pregnancy.
ganglionic layer of cerebellum the thin middle gray layer of the cortex of the cerebellum, consisting of a single layer of Purkinje cells.
germ layer (germ cell layer) any of the three primary layers of cells formed in the early development of the embryo (ectoderm, entoderm, and mesoderm), from which the organs and tissues develop.
germinative layer stratum germinativum.
granular layer
2. the deep layer of the cortex of the cerebellum.
3. the layer of follicle cells lining the theca of the vesicular ovarian follicle.
half-value layer the thickness of a given substance which, when introduced in the path of a given beam of rays, will reduce its intensity by one half.
Henle's layer the outermost layer of the inner root sheath of the hair follicle.
horny layer
2. the outer, compact layer of the nail.
malpighian layer stratum germinativum.
mantle layer the middle layer of the wall of the primordial neural tube, containing primordial nerve cells and later forming the gray matter of the central nervous system.
nervous layer all of the retina except the pigment layer; the inner layer of the optic cup.
odontoblastic layer the epithelioid layer of odontoblasts in contact with the dentin of teeth.
Ollier's layer the innermost layer of the periosteum.
prickle-cell layer stratum spinosum.
layer of rods and cones the layer of the nervous part of the retina, located between the pigmented part and the external limiting membrane, containing the sensory elements, the rods and cones.
spinous layer stratum spinosum.
spongy layer of endometrium a sublayer of the functional layer of endometrium, underlying the compact layer and containing the tortuous portions of the uterine glands.
subendocardial layer the layer of loose fibrous tissue uniting the endocardium and myocardium.
subepicardial layer the layer of loose connective tissue uniting the epicardium and myocardium.
zonal layer of thalamus a layer of myelinated fibers covering the dorsal surface of the thalamus.

germ lay·er

one of the three primordial cell layers (ectoderm, endoderm, mesoderm) established in an embryo during gastrulation.

germ layer

n.
Any of three cellular layers, the ectoderm, endoderm, or mesoderm, into which most animal embryos differentiate and from which the organs and tissues of the body develop through further differentiation.

germ layer

one of the three primordial cell layers formed during gastrulation in the early stages of embryonic development from which the entire range of body tissue is derived. Each germ layer has the potential for forming different cell types that differentiate into the various structures of the body. See also ectoderm, endoderm, mesoderm.

germ lay·er

(jĕrm lāĕr)
One of the three primordial cell layers (ectoderm, endoderm, mesoderm) established in an embryo during gastrulation.

germ layer

Any one of three layers of tissue, the ectoderm, the mesoderm and the endoderm, into which the embryo differentiates.

germ layer

any of the three embryonic layers of cells, ECTODERM, ENDODERM or MESODERM, that can be distinguished during development of the GASTRULA and for a short period after its formation.

germ lay·er

(jĕrm lāĕr)
One of three primordial cell layers established in an embryo during gastrulation.

layer

1. stratum; a sheetlike mass of tissue of nearly uniform thickness, several of which may be superimposed, one above the other, as in the epidermis.
2. a commercial fowl which is laying eggs, i.e. a female of more than about 5 months of age, up to the stage of being a 'spent hen' suitable only for slaughter.

basal layer
1. the deepest layer of the epidermis. See also stratum basale.
2. the deepest layer of the uterine mucosa.
blastodermic layer
germ layer (see below).
clear layer
stratum lucidum; the clear translucent layer of the epidermis, just beneath the horny layer.
columnar layer
1. layer of rods and cones.
2. mantle layer.
compact layer
the layer of the endometrium nearest the surface, containing the necks of the uterine glands.
functional layer
the compact and spongy layers of the endometrium considered together.
cerebellar ganglionic layer
the thin middle gray layer of the cortex of the cerebellum, consisting of a single layer of Purkinje cells.
germ layer
any of the three primary layers of cells formed in the early development of the embryo (ectoderm, entoderm and mesoderm), from which the organs and tissues develop.
germinative layer
any proliferative layer such as the basal layer of the epidermis or the lower layer of the claw, from which the claw grows.
granular layer
1. the layer of epidermis between the clear and prickle-cell layers; called also stratum granulosum.
2. the deep layer of the cortex of the cerebellum.
3. the layer of follicle cells lining the theca of the vesicular ovarian follicle.
horny layer
1. stratum corneum; the outermost layer of the epidermis, consisting of dead and desquamating cells.
2. the outer, compact layer of the claw, etc.
keratohyaline layer
granular layer (1).
mantle layer
the middle layer of the wall of the primitive neural tube, containing primitive nerve cells and later forming the gray matter of the central nervous system.
nervous layer
all of the retina except the pigment layer; the inner layer of the optic cup.
prickle-cell layer
stratum spinosum; the layer of the epidermis between the granular and basal layers, marked by the presence of prickle cells.
layer of rods and cones
a layer of the retina immediately beneath the pigment epithelium, between it and the external limiting membrane, containing the rods and cones.
spinous layer
prickle-cell layer.
spongy layer
the middle layer of the endometrium, containing the tortuous portions of the uterine glands.
subendocardial layer
the layer of loose fibrous tissue uniting the endocardium and myocardium.
zonal layer of thalamus
a layer of myelinated fibers covering the dorsal surface of the thalamus.
References in periodicals archive ?
These differentiated cells were immunohistochemically stained with primary antibodies against the antigens specific for different germ layers (a-fetoprotein (1:100) (AFP) for endoderm cells, [alpha]-actin (1:100) for mesoderm cells, Nestin (1:100), [beta]-Tubulin III (1:100) and GFAP (1:100) for ectoderm cells) (all antibodies purchased from Chemicon Co.
These results suggested that the pES cells could differentiate into various types of cells from three germ layers in vitro or in vivo.
The stem cell lines generated in the present study appear to have the same characteristics as other hESC lines, including expression of the same markers of pluripotency, self-renewing capacity, genetic stability, and ability to differentiate into derivatives of all three germ layers of the body.
The ability of phESC lines to form derivates from three germ layers that lead to all the cells found in a human body was proven by subcutaneous injection of the phESC into immunodeficient rats and mice and the subsequent formation of complex tissue structures called teratomas.
ES cells have distinct characteristics such as self-renewal and pluripotency, differentiating into all three germ layer and germ cell lineages (Kondoh et al.
2] Some of these trapped cells are totipotential blastomeres that can develop into any of the three germ layers.
The ectodermal dysplasias are a group of genetic disorders that affect the development of ectodermal tissues, the outermost tissues of the germ layers of the human embryo.
These proprietary human PluriCell lines display many of the usual characteristics of human ES cells, including the ability to differentiate into cell types of the three germ layers.
The ES cells differentiated into derivatives of all three germ layers both in vitro and in chimeric offspring and teratomas.
5, 1998--Human pluripotent stem cells -- cells with the demonstrated ability to differentiate in vitro into all three embryonic germ layers -- have been successfully derived in culture by scientists at the Johns Hopkins University School of Medicine, according to a paper to be published in the November 10 issue of Proceedings of the National Academy of Sciences.