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

Roller pump- type of blood pump, Roller Pump: This is the type most commo...

Roller Pump: This is the type most commonly used in clinical perfusion. It has a circular metal housing inside which there is a rotating urn with two rollers fixed at 180 degrees

What would most likely be true, You are given a metaphase chromosome prepar...

You are given a metaphase chromosome preparation (a slide) from an unknown organism that contains 12 chromosomes. Two that are clearly smaller than the rest appear identical in len

Compare & contrast replication, Compare and contrast replication, transcrip...

Compare and contrast replication, transcription, and translation based on the following criteria.   Criteria Replication Transcription

Explain the phylum molluska - mollusks, Explain the Phylum Molluska - Mollu...

Explain the Phylum Molluska - Mollusks? You are probably very familiar with members of this phylum. The mollusks include the octopuses, squids, cuttlefish, scallops, oysters, c

Example of codominance, In shorthorn cattle, the coat colours red or white ...

In shorthorn cattle, the coat colours red or white are controlled by a single pair of alleles. A calf which receives the allele for red coat from its mother and the allele for whit

Personal protective equipment, Personal Protective Equipment These eq...

Personal Protective Equipment These equipments are essentially required during working to protect face, eyes, respiratory system hands and clothes. Additionally in various in

The formation of macro and micronuclei of daughter paramoeci, The formation...

The formation of macro and micronuclei of daughter paramoeci: Each exconjugant has a single micronucleus and four macronuclei. This type of exconjugant divides twice and f

Explain about the lactose intolerance, Explain about the Lactose Intoleranc...

Explain about the Lactose Intolerance? Lactose is the name of the sugar found in milk. Lactose intolerance, you must be aware by now, occurs when the body is unable to breakdow

Tissue, What important changes will you find in the tissue of the fat perso...

What important changes will you find in the tissue of the fat person from those of a lean and thin person

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