Circulatory system - developmental changes, Biology

Assignment Help:

Circulatory System - Developmental Changes

We have learnt that throughout foetal life, gas exchange takes place, only through the placenta and not through lungs. Therefore, the foetus has various features in its circulatory systems that are not present in an adult. Diagram is a diagrammatic representation of foetal and infant circulation. In the foetus the oxygenated blood flowing back through the umbilical vein mainly bypasses the liver and goes to the right atrium.

2238_Circulatory System.png

Figure: Changes After Birth in Circulatory System

The blood then passes to the left atrium directly by an opening called foramen ovale. From the left atrium the blood flows to the left ventricle that sends the blood to the head and rest of the body. Blood returning from the head moves by the right atrium to the right ventricle which then does not pump the blood to the lungs but to a shunting vessel the ductus arteriosus that connects along with the descending aorta. A pair of umbilical arteries branch off from the aorta and carry deoxygenated blood to the placenta. At birth the umbilical artery and vein collapse while the cord is tied or the placenta separates, the result of it (here is negative pressure in the right atrium and blood flows back from the left atrium to the right. The flow causes the one way valve to close in the foramen ovale. Thus the left and right atria are separated. The shunting vessels which bypassed the liver and the lungs also collapse and adult pattern of circulation starts. The entire process takes place within a few hours of birth, though the permanent closure of foramen ovale may take up to a year.


Related Discussions:- Circulatory system - developmental changes

Body fluids of marine teleost, Body Fluids of Marine Teleost The body ...

Body Fluids of Marine Teleost The body fluids of marine teleost are hypotonic to seawater, so these fishes lose water to the environment especially across the gill epithelium.

Name of structures you would expect to find in the dermis, Name of the stru...

Name of the structures you would expect to find in the dermis. In the dermis you would expect to search sensory nerve endings, nerve fibres, capillaries, arterioles and venules

Define essential parts of photocolorimeter - sample cuvettes, Define Essent...

Define Essential Parts of Photocolorimeter - Sample Cuvettes? For accurate and precise reading, cuvette must be transparent, clean, devoid of any scratches and there should be

Give name of the cells capable of making gametes, Q. What is the name of th...

Q. What is the name of the cells capable of making gametes? What is the ploidy of these gamete-forming cells? The cells that form gametes are the germ cells as opposed to the s

Define the role of american dietetic association, Role of The American Diet...

Role of The American Dietetic Association The American Dietetic Association (ADA) remarked on the role of the dietitian in feeding dilemmas as:  the dietitian,  like other heal

What are immunoglobulins, Q. What are immunoglobulins? Immunoglobulin i...

Q. What are immunoglobulins? Immunoglobulin is the alternate name given to antibody and Immunoglobulins are complex proteins containing a variable portion and an invariable por

Fidelity - synthetic characters, Fidelity - Synthetic Characters Fidel...

Fidelity - Synthetic Characters Fidelity refers to the degree to which a species is restricted in its occurrence to a particular kind of community. The species with low fideli

Adult (post natal) stem cells-types of stem cells, Adult (Post natal) stem ...

Adult (Post natal) stem cells : act as repair system for the body replenishing specialized cells but also maintain the normal turnover of regenerative organs such as blood, skin o

Father, who is the father of science

who is the father of science

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