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

Illustrate about nervous system, Illustrate about Nervous System Functi...

Illustrate about Nervous System Functional unit of nervous system is neuron. Neuron is nerve cell. Information passes through neurons by nerve impulses. Nervous system corre

What are restriction enzymes, What are restriction enzymes? How do these en...

What are restriction enzymes? How do these enzymes participate in the recombinant DNA technology? The Restriction enzymes, or restriction endonucleases, are enzymes specialized

Explain japanese encephalitis, Japanese encephalitis  Japanese encephal...

Japanese encephalitis  Japanese encephalitis is an uncommon but potentially fatal mosquito-borne viral disease that occurs in rural Asia, especially near pig farms and rice pad

Define classification of carbohydrates - oligosaccharides, Define classific...

Define classification of carbohydrates - Oligosaccharides? Oligosaccharides are short chains of saccharide units and are condensation products of three to ten monosaccharides.

Pisces, which organs are involved in respiration of annelid and what is it ...

which organs are involved in respiration of annelid and what is it called ,what by products are formed and how amount of ATP is released?

How do grasslands differ from savannas, How do grasslands differ from Savan...

How do grasslands differ from Savannas? Name the two main categories of plant forms that dominate the desert vegetation.

Data gathering - steps in nursing process, Data Gathering   It is the g...

Data Gathering   It is the gathering of information about client's physical heath, mental outlook, social circumstances, family and community life, and other factors. To p

Causes of solid wastes, The main causes for the rapid growth in the quantit...

The main causes for the rapid growth in the quantity of solid wastes are- (i)     Over population: the ever increasing population is increasing all types of pollution; same is t

Explain hepatitis a and b, Hepatitis A/B  A combination vaccine contain...

Hepatitis A/B  A combination vaccine containing the same antigenic components as  Engerix-B and pediatric  Havrix (Twinrix - GlaxoSmithKline) is available for patients >18 year

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