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

Infectious laryngotracheitis, I nfe c tio u s laryngotracheitis It...

I nfe c tio u s laryngotracheitis It is a slow, laterally spreading respiratory disease of chickens, pheasants, peafowl and turkeys caused by a herpes virus with high morb

Sarcolemma, Normal 0 false false false EN-IN X-NONE ...

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

Ecology, does jellyfish depend on solarenergy

does jellyfish depend on solarenergy

Explain the inferior dental nerve, Explain the inferior dental nerve T...

Explain the inferior dental nerve The inferior dental nerve in some cases may divide into two or three rami that occupy separate canals as the nerve travels in the mandible to

Define oxidised starch, Oxidised starch Oxidised starch finds a number ...

Oxidised starch Oxidised starch finds a number of uses in the food industry where a neutral tasting, low viscosity 'body builder' is required as in lemon curd manufacture, in s

Explain energetic function of organic molecules, What are some examples of ...

What are some examples of the energetic function of organic molecules? As they are complex molecules, presenting lots of chemical bonds, organic molecules keeps large amount of

Determine the sexual arousal mechanism, How does the sexual arousal mechani...

How does the sexual arousal mechanism in women facilitate fecundation? During sexual arousal in women the vagina secretes substances to neutralize its acidity therefore allowin

Demonstrate the cause of the mutant trait, A protein that is normally a sin...

A protein that is normally a single-pass transmembrane protein is absent from the cell surface of the mutant cell line YTM-15. When labeled so that the protein can be localized, yo

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