Explain Gastrulation in human embryos?

Question

my main concern is to know about morphogenetic movement.

Answer 1

Gastrulation in Human Embryo



Delamination precedes gastrulation separating ICM into epiblast & hypoblast

Gastrulation occurs in epiblast (future embryo)

Gastrulation involves several types of movements and shape changes

End product is three germ layers: ectoderm, endoderm and mesoderm

The expression of certain genes regulates the formation of the embryonic axes & the organization of the embryo

The Timing of Gastrulation and Subsequent Events

Gastrulation begins about 15 days of development and is followed by neurulation and the start of development of several major organ systems



Role of Gastrulation

Gastrulation will covert the bilaminate epiblast into the three primary embryonic germ layers

Ectoderm: outside; this embryonic layer more or less surrounds the other germ layers

Mesoderm: middle; this germ layer lies between the ectoderm and mesoderm

Endoderm: inside; this germ layer lies at the most interior of the embryo

Subsequently neurulation will form epithelial and neural ectoderm from the ectoderm



During human gastrulation, cells move over the blastodisc surface, enter the primitive streak and move internally. On the surface they move in association with other cells but once they turn the corner around the lip of the primitive streak the cells separate as individuals to migrate internally to form the mesoderm and endoderm. These are just some of the types of cell movements that occur in animal embryos. Here's a full list



Ingression: cells break away from the tissue and migrate as individuals

Delamination: layers of cells separate from each others more or less as sheets of cells

Intercalation: two cell layers interlace with each other

Epiboly: a form of cell spreading in which cells flatten out; this allows them to cover a much larger surface area (1st detailed in frog development).

Invagination (Evagination): a tissue layer folds in (out)

Involution: cells move over a lip of tissue and into the interior

Convergent Extension: cells reorganize to form less layers allowing the cells to extend out from a point.

Not all of these morphogenetic movements have been detailed in humans but they all have been shown to occur in other animals. Also remember, one type of cellular rearrangement does not exclude another with several different types of movement potentially occurring at the same time.

Answer 2

gastrulation





Gastrulation is a phase early in the development of animal embryos, during which the morphology of the embryo is dramatically restructured by cell migration. Gastrulation varies in different phyla; the following description concerns the gastrulation of the echinoderms, representative of the triploblasts, or animals with three embryonic germ layers.



At the beginning of gastrulation, the embryo is hollow ball of cells known as the blastula, with an animal pole and a vegetal pole. The vegetal pole begins to flatten and then invaginates into the interior, replacing the blastocoelic cavity and thereby forming a new cavity, the archenteron (literally: primitive gut), the opening into which is the blastopore. Some of the cells of the vegetal pole detach and become mesenchyme cells. The mesenchyme cells divide rapidly, migrate to different parts of the blastocoel, and form filopodia, strands that help to pull the tip of the archenteron towards the animal pole. Once the archenteron reaches the animal pole, a perforation forms, and the archenteron becomes a digestive tract passing all the way through the embryo.



The three embryonic germ layers have now formed. The endoderm, consisting of the archenteron, will develop into the digestive tract. The ectoderm, consisting of the cells on the outside of the gastrula that played little part in gastrulation, will develop into the skin and the central nervous system. The mesoderm, consisting of the mesenchyme cells that have proliferated in the blastocoel, will become all the other internal organs.



Gastrulation is followed by the organogenesis, during which the individual organ anlagen of the embryo are set up within the newly formed germ layers. Part of the organogenesis is the Neurulation.

Answer 3

Gastrulation In Humans

Answer 4

Human Gastrulation

Answer 5

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Explain Gastrulation in human embryos?

my main concern is to know about morphogenetic movement.