Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Extra-Embryonic Membranes and Placenta
The extra embryonic membranes like you already know provide nourishment and protection. These membranes are fundamentally similar to the extra-embryonic membranes of reptiles and birds, however the method of origin differs in humans. During the third and fourth week, the amnion grows around the embryo enclosing it in a membranous fluid filled sac in which the growing embryo and later the foetus floats and can move freely. This sac as mentioned in the previous section is a shock absorber and encloses a fluid, the amniotic fluid, that helps to keep the temperature of foetal environment stable. Another membrane, the chorion develops from the trophoblast cells. The chorion is a extremely specialised extraembryonic tissue. It facilitates the transfer of gases, nutrients and wastes among the embryo and the mother. It is the primary part of the placenta that we will study a little later. Yolk sac develops during the second week of development even though there is no yolk in the human egg. It does not give nourishment to the embryo but it becomes surrounded by mesoderm that forms the blood cells till the liver of the embryo becomes functional in the sixth week. The yolk sac with the allantois forms the umbilical cord. Part of the yolk sac also forms the lining of the gut. The allantois that forms during the third week of development is a tiny sausage shaped pouch on the yolk sac. It also is accountable for producing blood cells and later develops into the umbilical blood vessels.
Describe two differences among green algae and plants. Algae lack tissue differentiation and have no true roots, leaves and stems. The gametangia of algae are single-celled; th
Surgical significance of Inferior alveolar nerve and artery In an excessively resorbed ridge, the mental foramen with its contents of mental nerve and vessels, can be found o
What are the benefits of Soil testing Soil testing is done to assess the nutrient supplying capacity of the soil. The data obtained as a result of testing is useful for recom
What are the main theoretical models that try to explain the formation of the enzyme-substrate complex? There are two major models that explain the formation of the enzyme-subs
Explain Alternate Photosynthetic Pathways? An alternate photosynthetic pathway is the C4 pathway, where plants incorporate carbon into four-carbon compounds instead of 3PG. Thi
How to draw diagrams of bones
What is Biochemical Characteristics? In the last section we have learnt about the importance of biochemical tests. It must be clear now that biochemical tests are used to -
Q. Economic aspect of biodiversity? Biodiversity serves as an income generating activity for countries around the world. Many people visit forests, beaches, mountains, grasslan
Soil Mixing The larger soil organisms are responsible for considerable mechanical mixing and weathering of soil. The wedge-like action of roots and other underground plant orga
Explain the difference between meiosos and mitosis
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!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd