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

What is bilateral symmetry system, What is Bilateral Symmetry system? T...

What is Bilateral Symmetry system? To review: all animals besides the sponges (Phylum Porifera) belong to the Eumetazoa. There are two groups within the Eumetazoa that possess

Explain the interaction of vitamin a with vitamin e, Explain the Interactio...

Explain the Interaction of Vitamin A with Vitamin E? Of the various nutrients, the interaction of vitamin E, proteins, zinc and iron with vitamin A is of significance. Know? Le

Techniques of closed heart surgery, Techniques :  Depending on the type of...

Techniques :  Depending on the type of surgery planned, the heart may be approached through median sternotomy, left or right thoracotomy. The problems encountered could be due to

Explain the malthus theory about population growth, Explain the Malthus' Th...

Explain the Malthus' Theory about population growth? Darwin's Theory was also based on Thomas Malthus' writings on population growth, in which he explained that populations gro

Characteristics of population, CHARACTERISTIC S OF POPULATION - Each p...

CHARACTERISTIC S OF POPULATION - Each population envolves adaptations suited to its own locality. Population is unit of evolution. Population is also an ecological uni

Tolerance to cold and freezing temperatures, Normal 0 false f...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Importance of forests - habitat and food, Importance of Forests - Habitat a...

Importance of Forests - Habitat and Food Forests provide habitat, and food as well as protection to wildlife species against extremes of climate and help in balancing carbon d

What is phenotypical proportion, Considering hybridization in a given trait...

Considering hybridization in a given trait like the color of the hair of a mammalian species (white/black) conditioned by a pair of different alleles under complete dominance (blac

BiologicaL METHODS.., GIVE THE SHORT DETAIL OF HE BIOLOGICAL METHODS

GIVE THE SHORT DETAIL OF HE BIOLOGICAL METHODS

Ilustrate the binding of atp to actin, Which of the following is true in a ...

Which of the following is true in a skeletal muscle? A. Movement of the cross-bridge occurs only when the myosin head is detached from the actin molecule. B. The binding of

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