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

Define food science and simple sugars, Define Food Science and Simple Sugar...

Define Food Science and Simple Sugars? This first unit introduces the concept, scope and importance of food science and technology as a discipline. It further presents a detail

Disorder of adrenal function, Disorder  of Adrenal Function: The diso...

Disorder  of Adrenal Function: The disorders of  adrenal function may lead  to acute and chronic  .adrenocortical insufficiency. Let  us briefly  describe each  one as follows

Explain dietetics, Explain Dietetics Dietetics  has been defined as  t...

Explain Dietetics Dietetics  has been defined as  the science and art of feeding individuals based  on the principles of  nutrition. It can also be  said  to  be  the "science

What is the plant hormone remarkable for stimulating, What is the plant hor...

What is the plant hormone remarkable for stimulating flowering and fruit ripening? What are the uses and practical inconveniences of that hormone? The plant hormone notable for

Explain the disadvantages of fixation, Explain the Disadvantages of Fixatio...

Explain the Disadvantages of Fixation? Fixation has following disadvantages also. These are highlighted herewith: (i) It distorts the cell's appearance. (ii) Motility can

Plasmotomy, draw a well labled diagram of plasmotomy

draw a well labled diagram of plasmotomy

What would be the knowledge of regeneration, A 19 year old model for Glamou...

A 19 year old model for Glamour magazine tripped over an extension cord causing injury to her epidermis. She is afraid the injury will leave a scar. Based on your knowledge of rege

Difference between aqueous humour and vitreous humour, Difference between a...

Difference between aqueous humour and vitreous humour - Aquou s Humour Vitrou s humour 1. Occurs in aquous chamber   2. Wat

What is the purpose to use hydrocolloids, Hydrocolloids are extremely versa...

Hydrocolloids are extremely versatile and are used for many other purposes including: (a) Production of pseudoplasticity  (i.e. fluidity under shear) at high temperatures to ea

Explain about the micronutrient deficiencies, Explain about the Micronutrie...

Explain about the Micronutrient Deficiencies? Micronutrient deficiencies are more common during calamities. Can you guess, why? This is due to the lack of diversified food item

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