germ layer

layer /lay·er/ (la´er) a stratum or lamina.

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bacillary layer  l. of rods and cones.

basal layer  stratum basale.

blastodermic layer  germ l.

layers of cerebral cortex  six anatomical divisions (I–VI) of the cerebral cortex (specifically the neocortex), distinguished according to the types of cells and fibers they contain.

clear layer  stratum lucidum.

columnar layer  mantle l.

compact layer of endometrium  stratum compactum.

enamel layer  either of two walls, the inner concave wall or the outer convex wall, of the enamel organ.

functional layer of endometrium  stratum functionale.

ganglionic layer of cerebellum  Purkinje l.

germ layer  any of the three primary layers of cells of the embryo (ectoderm, endoderm, and mesoderm), from which the tissues and organs develop.

germinative layer  stratum germinativum.

granular layer 

1. stratum granulosum.

2. the deep layer of the cortex of the cerebellum.

Henle's layer  the outermost layer of the inner root sheath of the hair follicle.

horny layer  stratum corneum.

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.

odontoblastic layer  the epithelioid layer of odontoblasts in contact with the dentin of teeth.

prickle cell layer  stratum spinosum.

Purkinje layer , Purkinje cell layer the layer of Purkinje neurons situated between the external molecular layer and the internal granular layer of the cerebellar cortex.

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  stratum spinosum.

spongy layer of endometrium  stratum spongiosum.

subendocardial layer  the layer of loose fibrous tissue uniting the endocardium and myocardium and containing the vessels and nerves of the conducting system of the heart.

subepicardial layer  the layer of loose connective tissue uniting the epicardium and myocardium.

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

germ layer endoderm and adjacent germ layers

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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.

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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.

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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.