germ layer

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

1. 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.

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

1. stratum corneum.

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.

Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

germ lay·er

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

Farlex Partner Medical Dictionary © Farlex 2012

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.

The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.

germ lay·er

(jĕrm lāĕr)

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

Medical Dictionary for the Health Professions and Nursing © Farlex 2012

germ layer

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

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

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.

Collins Dictionary of Biology, 3rd ed. © W. G. Hale, V. A. Saunders, J. P. Margham 2005

germ lay·er

(jĕrm lāĕr)

One of three primordial cell layers established in an embryo during gastrulation.

Medical Dictionary for the Dental Professions © Farlex 2012