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

Composition-atmosphere, Composition The present day composition of atmo...

Composition The present day composition of atmosphere is the product of a lengthy evolutionary process that began more than four billion years ago. It is composed of a mixture

What are some things that have algae in them, What are some things that hav...

What are some things that have algae in them? Yeast is considered Algae.

Determine the signs and symptoms of bulimia, Determine the Signs and Sympto...

Determine the Signs and Symptoms of Bulimia? 1. Binges, minimum twice a week for three months 2. Purging a Menstrual irregularities 3. Swollen glands Frequent fluct

What is paediatric clinical literature, What is paediatric clinical literat...

What is paediatric clinical literature The paediatric clinical literature has expanded greatly in its coverage of the wide variety of medical circumstances that can negatively

Determine the importance of clinical studies, Determine the importance of C...

Determine the importance of Clinical Studies The opportunity to investigate the conditions that influence stages of growth and development from gestation to infancy to early ch

Respiration, Can you define respiration in 5 oganisms

Can you define respiration in 5 oganisms

Explain in details amino acid, Explain in details Amino Acid? Amino Ac...

Explain in details Amino Acid? Amino Acids :   There are 20 common amino acids, with a few more found in lower organisms. Adult humans require a diet that includes at least 8

Eggs of hen, EGG S OF HEN It is a meiolecithal egg which is oval. T...

EGG S OF HEN It is a meiolecithal egg which is oval. The animal pole is found in the form of a small germinal disc. The vegital pole has two types of yolk viz. White yol

Protozoa, What are the disadvantages of protozoa

What are the disadvantages of protozoa

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