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 toxicity of nicotinic acid, Explain the Toxicity of nicotinic a...

Explain the Toxicity of nicotinic acid? Although therapeutically useful in lowering serum cholesterol, administration of chronic high oral doses of nicotinic acid can lead to h

What is the water cycle, Q. What is the water cycle? The water cycle re...

Q. What is the water cycle? The water cycle represents the recycling and circulation of water in nature. The Liquid water on the planet surface is heated by the sun and turns i

What is a monohybrid cross, A monohybrid cross: A.Determines the genetic ma...

A monohybrid cross: A.Determines the genetic makeup of an organism B.always involves homozygous alleles. C.always involves organisms that are heterozygous at all loci. D.Always inv

Botany, subject for botany assignment

subject for botany assignment

Difference between lamarckism and neo-lamarckism, DIFFERENC E BETWEEN LAMA...

DIFFERENC E BETWEEN LAMARCKISM AND NEO-LAMARCKISM - S.No Lamarckism Neo-Lamarckism 1. It refers of the original

Explain water-soluble and fat-soluble vitamins, What is the difference betw...

What is the difference between water-soluble and fat-soluble vitamins? Why can fat-soluble vitamins cause harm when ingested in excess? Water-soluble vitamins are those soluble

Explain identification of cancer cells from normal cells, Explain Identific...

Explain Identification of Cancer Cells from Normal Cells? Cancer cells can be distinguished from normal cells by examining them under a microscope. In a specific tissue cancer

What is lamarckism, What is lamarckism? The Lamarckism is the theory th...

What is lamarckism? The Lamarckism is the theory that unites the law of use and disuse with the law of the transmission of acquired characteristics that is that asserted that a

Aetiology, Aetiology:   A List Of The Causes Of A Disease  (Description Of ...

Aetiology:   A List Of The Causes Of A Disease  (Description Of The Characteristic Causes) Factors Which Influence The Onset Of Disease:  Include "Risk Factors", Life-Style, Sex, A

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