Third week - embryonic development, Biology

Assignment Help:

Third Week - Embryonic Development

Throughout the third week of development the ICM separates from the uophoblast and forms the flattened embryonic disc, which at first consists of cells of all three germ layers, ectoderm, endoderm and mesoderm and is termed as the epiblast. From this a lower layer separates to form the endoderm. The second layer, mesoderm, forms through the migration of cells through the primitive streak that forms as the embryonic disc elongates. The cells remaining in the upper layer make the ectoderm. These three germ layers will give rise to all the organs of the body as pointed out in Figure.

2006_Third Week.png

Figure: The organs of the body form from the three germ layers

The embryo's heart as well begins its development as a pair of microscopic tubes. The cardiovascular system is the first system to become functional in the embryo. At the end of the 3rd week the heart tubes fuse and become linked to the blood vessels in the embryo, body stalk, chorion and yolk sac, to make a primitive blood circulatory system. Chorionic villi (that will form the placenta later) also begin to form during this period.


Related Discussions:- Third week - embryonic development

Physiological regeneration, Physiological Regeneration This type of r...

Physiological Regeneration This type of regeneration is a regular physiological function including the continuous replacements of cells and tissues, and thus is indispensible

Fensom and spanner electroosmotic flow hypothesis, Fensom and Spanner Elect...

Fensom and Spanner Electroosmotic Flow Hypothesis In electroosmosis the ions flow across a membrane in response to electrical gradient. Ions pull along water and other content

Sun, wath is sun

wath is sun

Nutrition, Why is holophytic nutrition a mode of autotrophic nutrition

Why is holophytic nutrition a mode of autotrophic nutrition

Phylum platyhelminhes, what are the classification of phylum platyhelminthe...

what are the classification of phylum platyhelminthes?

Ringworms (cutaneous mycoses), Ringworms (cutaneous mycoses) Cutaneous...

Ringworms (cutaneous mycoses) Cutaneous mycoses – also called dermatomycoses, occur worldwide and represent the most common fungal diseases in humans. The dermatophytes are th

What is the use of adrenergic receptor, Q. What is the use of Adrenergic Re...

Q. What is the use of Adrenergic Receptor? Adrenergic Receptors are also subdivided into 2 major categories: ALPHA α - or- BETA β In general, when NE (E) binds to alpha r

Explain the nutritional and functional role of magnesium, Minerals :- Magne...

Minerals :- Magnesium    Food Source      Whole grains, nuts, legumes, green leafy vegetables Nutritional Functional role Essential nutrient: Deficiency is rare Co

Explain intraoral barrier techniques, Q. Explain Intraoral Barrier Techniqu...

Q. Explain Intraoral Barrier Techniques? Rubber dam A rubber dam is used whenever possible for improved vision and access and to reduce dental personnels' exposure to micr

1.notochord, general character and classification of platyhelminthes

general character and classification of platyhelminthes

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd