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 reduction, What is reduction? The most commonly understood defi...

What is reduction? The most commonly understood definition of reduction is the removal of oxygen or addition of hydrogen ions. However, chemically, reduction can be defined as

What is posterior aneurysm? , What is  Posterior Aneurysm? The te...

What is  Posterior Aneurysm? The technique of Posterior Aneurysm operation is the same. Care must be taken to avoid injury to the posterior papillary muscle and poster

Determine the recombination frequency of genes, Why does the recombination ...

Why does the recombination frequency of genes vary with the distance between them in the chromosome? The farther the distance among the loci of two genes in a chromosome the h

Surgical endodontic & retrograde sealing of immature root, Conventional End...

Conventional Endodontic Treatment Surgical Endodontic & Retrograde sealing of Immature root Apex: After cleaning and shaping of the RC and before filling , I make a surgical

What is prostaglandins , Prostaglandins and the structurally associated mol...

Prostaglandins and the structurally associated molecules prostacyclins, leukotrienes and thromboxanes, are called as eicosanoids because they having 20 carbon atoms. These hormones

Describes the tenants of pangenesis theory, Which of the following best des...

Which of the following best describes the tenants of Pangenesis Theory? A. The hereditary material is composed in every organ/tissue and is transmitted to the next generation b

Are gametes always made by meiosis, Q. Are gametes always made by meiosis? ...

Q. Are gametes always made by meiosis? In the haplontic haplobiontic life cycle and in the plant life cycle (diplobiontic life cycle) gametes are made by mitosis and not by mei

Explain observation or inference required for osazone test, Explain Observa...

Explain Observation or Inference required for osazone test? 1. Crystals of different shapes will be seen. Glucose and fructose give needle shaped crystals and galactose gives f

Health hazards with poor management of bio-medical waste, Health Hazards wi...

Health Hazards with poor management of Bio-medical waste Health hazards associated with poor management of Bio-medical waste are: - Injury from sharps to staff and waste han

Deficiency diseases-thiamine deficiency (hypothiaminosis), Thiamine deficie...

Thiamine deficiency (hypothiaminosis) Thiamine deficiency is characterized by signs of nervous system. The primary  thiamine deficiency is not common in animals. However, seco

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