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

Blunt injury, Blunt Injury Closed penumothorax  Tension pneumoth...

Blunt Injury Closed penumothorax  Tension pneumothorax  Tracheobronchial injury  Fracture ribs and flail chest  Mediastinal injury

How would a glycosidic bond present, A glycosidic bond would be present in:...

A glycosidic bond would be present in: Select one: a. acetone. b. methyl-alpha-D-glucose. c. 2-deoxy-beta-D-ribose. d. glucose-6-phosphate. e. fructose-1, 6-bisphosp

State the foot examination of a diabetic patient, State the Foot examinatio...

State the Foot examination of a diabetic patient Foot examination of a diabetic patient is very crucial in early detection and proper treatment of foot problems.  In every fol

Define bioactive substances from protein foods, Define Bioactive Substances...

Define Bioactive Substances from Protein Foods? Bioactive substances are derived from living organisms that can be used by humans for a variety of applications. They are consti

Main constituents of the earth''s atmosphere in our time, What are the main...

What are the main constituents of the earth's atmosphere in our time? The present atmosphere of the earth is constituted essentially of molecular nitrogen (N2) and molecular ox

Explain three parts of homogenate, Differential centrifugation divides cell...

Differential centrifugation divides cellular components based on the differences in their size and / or density. A tissue sample was homogenized and three parts (aliquots) of this

Explain the transcription factor of zinc, Explain the Transcription Factor ...

Explain the Transcription Factor of Zinc? Zinc is an important structural component of DNA- binding proteins also known as 'transcription factors'. These transcription factors

Classification of freshwater ecosystems, Classification of Freshwater Ecosy...

Classification of Freshwater Ecosystems Fresh water ecosystems depend on the terrestrial ecosystems for large quantities of organic and inorganic matter which are constantly a

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