Definition of ectoderm in English:

ectoderm

nounˈɛktə(ʊ)dəːmˈɛktəˌdərm

mass nounEmbryology Zoology

The outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis, nerve tissue, and nephridia.
〔动，胚〕外胚层；由外胚层形成的组织；外层。比较ENDODERM 和MESODERM
Compare with endoderm and mesoderm
Example sentencesExamples
- The branchial arches begin as cylindrical cores of mesenchyme sandwiched between continuous sheets of epidermal ectoderm and internal endoderm.
- At a tissue level, an adult hydra is essentially a tube composed of two tissue layers, the ectoderm and the endoderm, which extend throughout the animal.
- The presumptive neural tube tissues consist of a layer of ectoderm along the dorsal midline of the embryo, between the notochord and an outer layer of epidermis.
- It is involved in mesoderm development and differentiation of the neural ectoderm into epidermoblasts and neuroblasts.
- The anthozoans are diploblastic animals developing from two epithelial germ cell layers: the ectoderm, facing the seawater, and the endoderm, facing the gastrovascular cavity or coelenteron.

Derivatives

ectodermal

adjectiveɛktə(ʊ)ˈdəːm(ə)lˌɛktəˈdərm(ə)l

Embryology Zoology

As the neural tube closes, the ectodermal cells continue to grow and divide very rapidly.
Example sentencesExamples
- For example, chaetal sacks are one of the few ectodermal features of polychaetes that regularly express engrailed, and chaetae are the primary indurated elements in the ectoderm.
- The term iteration is used to denote processes that result in both metameric segments and repeated ectodermal skeletal structures.
- At the very tip of the limb bud is a thickening in the ectoderm - the apical ectodermal ridge or apical ridge, which runs along the dorso-ventral boundary.
- In most polychaetes, the ectodermal and mesodermal derivatives of the growth zone become incorporated into segmental tissues in an anterior-posterior sequence.

Origin

Mid 19th century: from ecto- 'outside' + Greek derma 'skin'.

Definition of ectoderm in US English:

ectoderm

nounˈɛktəˌdərmˈektəˌdərm

Embryology Zoology

The outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis and nerve tissue.
〔动，胚〕外胚层；由外胚层形成的组织；外层。比较ENDODERM 和MESODERM
Compare with endoderm and mesoderm
Example sentencesExamples
- It is involved in mesoderm development and differentiation of the neural ectoderm into epidermoblasts and neuroblasts.
- The presumptive neural tube tissues consist of a layer of ectoderm along the dorsal midline of the embryo, between the notochord and an outer layer of epidermis.
- At a tissue level, an adult hydra is essentially a tube composed of two tissue layers, the ectoderm and the endoderm, which extend throughout the animal.
- The anthozoans are diploblastic animals developing from two epithelial germ cell layers: the ectoderm, facing the seawater, and the endoderm, facing the gastrovascular cavity or coelenteron.
- The branchial arches begin as cylindrical cores of mesenchyme sandwiched between continuous sheets of epidermal ectoderm and internal endoderm.

Origin

Mid 19th century: from ecto- ‘outside’ + Greek derma ‘skin’.

单词	ectoderm
释义	Definition of ectoderm in English: ectoderm nounˈɛktə(ʊ)dəːmˈɛktəˌdərm mass nounEmbryology Zoology The outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis, nerve tissue, and nephridia. 〔动，胚〕外胚层；由外胚层形成的组织；外层。比较ENDODERM 和MESODERM Compare with endoderm and mesoderm Example sentencesExamples The branchial arches begin as cylindrical cores of mesenchyme sandwiched between continuous sheets of epidermal ectoderm and internal endoderm. At a tissue level, an adult hydra is essentially a tube composed of two tissue layers, the ectoderm and the endoderm, which extend throughout the animal. The presumptive neural tube tissues consist of a layer of ectoderm along the dorsal midline of the embryo, between the notochord and an outer layer of epidermis. It is involved in mesoderm development and differentiation of the neural ectoderm into epidermoblasts and neuroblasts. The anthozoans are diploblastic animals developing from two epithelial germ cell layers: the ectoderm, facing the seawater, and the endoderm, facing the gastrovascular cavity or coelenteron. Derivatives ectodermal adjectiveɛktə(ʊ)ˈdəːm(ə)lˌɛktəˈdərm(ə)l Embryology Zoology As the neural tube closes, the ectodermal cells continue to grow and divide very rapidly. Example sentencesExamples For example, chaetal sacks are one of the few ectodermal features of polychaetes that regularly express engrailed, and chaetae are the primary indurated elements in the ectoderm. The term iteration is used to denote processes that result in both metameric segments and repeated ectodermal skeletal structures. At the very tip of the limb bud is a thickening in the ectoderm - the apical ectodermal ridge or apical ridge, which runs along the dorso-ventral boundary. In most polychaetes, the ectodermal and mesodermal derivatives of the growth zone become incorporated into segmental tissues in an anterior-posterior sequence. Origin Mid 19th century: from ecto- 'outside' + Greek derma 'skin'. Definition of ectoderm in US English: ectoderm nounˈɛktəˌdərmˈektəˌdərm Embryology Zoology The outermost layer of cells or tissue of an embryo in early development, or the parts derived from this, which include the epidermis and nerve tissue. 〔动，胚〕外胚层；由外胚层形成的组织；外层。比较ENDODERM 和MESODERM Compare with endoderm and mesoderm Example sentencesExamples It is involved in mesoderm development and differentiation of the neural ectoderm into epidermoblasts and neuroblasts. The presumptive neural tube tissues consist of a layer of ectoderm along the dorsal midline of the embryo, between the notochord and an outer layer of epidermis. At a tissue level, an adult hydra is essentially a tube composed of two tissue layers, the ectoderm and the endoderm, which extend throughout the animal. The anthozoans are diploblastic animals developing from two epithelial germ cell layers: the ectoderm, facing the seawater, and the endoderm, facing the gastrovascular cavity or coelenteron. The branchial arches begin as cylindrical cores of mesenchyme sandwiched between continuous sheets of epidermal ectoderm and internal endoderm. Origin Mid 19th century: from ecto- ‘outside’ + Greek derma ‘skin’.
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