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

Illustrate the tear flow direction of drainage, Illustrate the tear flow di...

Illustrate the tear flow direction of drainage. Tear Drainage: Tear are drained by the combined action of gravity, capillary action and lid movements (Lacrimal pump)

List the benefits of lsm, List the benefits of LSM. Life style modifica...

List the benefits of LSM. Life style modification helps in the following ways: - Reduction of weight - Good sugar control - Good blood pressure control - Reduction

Explain e. coli - microbiological study of water, Explain E. coli - Microbi...

Explain E. coli - Microbiological Study of Water? It is always present in human intestine so its presence indicates the faecal pollution and possible presence of other human or

Explain fomivirsen, Explain Fomivirsen  Fomivirsen, an  antisense olig...

Explain Fomivirsen  Fomivirsen, an  antisense oligonu- cleotide, is FDA-approved for intravitreal treatment of CMV retinitis in HIV-infected patients who cannot tolerate or ha

Describe cultural characteristics of microorganisms, Q. Describe Cultural C...

Q. Describe Cultural Characteristics of Microorganisms? Bacterial growth in and on foods often is extensive enough to make the food unattractive in appearance or otherwise obj

Can serotonin used in consciousness, Q. Can Serotonin used in consciousness...

Q. Can Serotonin used in consciousness? Serotonin complements the action of noradrenalin and acetylcholine in promoting wakefulness and cortical responsiveness. Experiments pro

Explain biological function, Q. Concerning their biological function what i...

Q. Concerning their biological function what is the difference between meiosis and mitosis? The main biological function of mitosis is cellular multiplication a fundamental pro

What are the destinations of those oxygen atoms, Photosynthesis is the most...

Photosynthesis is the most significant producer of molecular oxygen (O2) on our planet. From which molecule do oxygen atoms liberated by photosynthesis come? From which other molec

Explain about the dehydration or drying, Explain about the Dehydration or D...

Explain about the Dehydration or Drying? The technique of drying is the oldest method of food preservation practiced by mankind. The removal of moisture, which is actually dehy

Explain the jejuno ileal bypass and jaw wiring, Explain the Jejuno ileal By...

Explain the Jejuno ileal Bypass and Jaw Wiring? Jejuno-ileal Bypass: Absorptive surface of the small intestines can also be reduced through surgery called the jejuno-ileal by p

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