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

Explain the treatment of travelers diarrhea, Treatment of travelers'diarrhe...

Treatment of travelers'diarrhea  The most common cause of travelers' diarrhea, usually a self-limited illness lasting several days, is infection with noninvasive enterotoxigeni

Golgi complex, GOLGI COMPLEX ( GOLGI APPARATUS = GOLGI BODY) The Nobel ...

GOLGI COMPLEX ( GOLGI APPARATUS = GOLGI BODY) The Nobel laureate, Camilla  Golgi (1898)  discovered  the  presence of a special,  small group  of interconnecting  membranous  s

Difference between algae and protozoans, Q. What is the fundamental differe...

Q. What is the fundamental difference between algae and protozoans? The basic difference between algae and protozoans is the fact that algae are photosynthetic autotrophs while

Describe aortic regurgitation murmur in chronic ar murmur, Describe Aortic ...

Describe Aortic Regurgitation Murmur in Chronic AR Murmur ? Characteristic: High pitched, decrescendo murmur, immediately after S2 and extending through and part or all of dias

Define reagents estimation of iron in the solution, Define Reagents Estimat...

Define Reagents Estimation of Iron in the Solution? 1. Conc. sulphuric acid (iron free) 2. Conc. potassium permanganate solution 3. Saturated potassium persulphate (K 2 S

Issues impacting health and development -inefficiency, Normal 0 ...

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

What do you understand by haemagglutinins, Q. What do you understand by Hae...

Q. What do you understand by Haemagglutinins? Haemagglutinins are the globulin type of proteins which are present in the seeds of plants like double bean, field bean, white be

What is the difference between taeniasis and cysticercosis, What is the dif...

What is the difference between taeniasis and cysticercosis? Taeniasis is the parasitic disease caused by the adult tapeworm installed within the human intestine. Cysticercos

Cytokinins - plant growth substances, Cytokinins - Plant Growth Substances ...

Cytokinins - Plant Growth Substances Folke Skoog observed that the cell division or differentiation is affected by AMP and other purines. A nucleic acid from yeast was also fo

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