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

What happens when the ovum is fertilized, What happens when the ovum is fer...

What happens when the ovum is fertilized? If the ovum is fertilized, there is no breakdown of endometrium and no menstrual flow. The fertilized ovum travels through uterine tub

Can you explain para-sternal view, Q. Can you explain Para-sternal View? ...

Q. Can you explain Para-sternal View? Various congenital anamolies can be detected in this view are perimembranous VSD (transducer anbled towards right hip), doubly commit

Explain about spring model, Q. Explain about Spring Model ? The spring ...

Q. Explain about Spring Model ? The spring model depicts elasticity. A force is applied in terms of load onto the spring as illustrated in the figure 8.6. When the force is app

Metabolic alterations and nutritional problems - cancer, Metabolic Alterati...

Metabolic Alterations and the Resultant Nutritional Problems/ Clinical Manifestations Associated With Cancer? Several research studies have shown that malignant growth (cancer)

Agro industrial-calcium, Calcium   The calcium content in forages is affe...

Calcium   The calcium content in forages is affected by species, plant part (leaf versus stem), plant maturity, soil content of calcium and climate. Forages are usually a good so

Can pathophysiology causes cardiovascular disease, Q. Can Pathophysiology c...

Q. Can Pathophysiology causes cardiovascular disease? Cigarette use activates platelets, increases circulating fibrinogen, increases heart rate, and elevates blood pressure. It

What is the full chemical equation of photosynthesis, Q. What is the full c...

Q. What is the full chemical equation of photosynthesis? The full chemical equation of photosynthesis is given below: 6 CO 2 + 12 H 2 O + light --> C 6 H 12 O 6    + 6 H 2

Explain about the term- therapeutic, Explain about the term- Therapeutic ...

Explain about the term- Therapeutic Therapeutic approaches that scientists are pursuing include transplanting cells to replace those which are damaged or using growth factors

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