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

Regulation of pfk and fructose 1, When the level of AMP is high, this shows...

When the level of AMP is high, this shows the requirement for more ATP synthesis. AMP stimulates PFK increases the rate of glycolysis and inhibits fructose 1 and 6- bisphosphatase

Complications of making a definite classification, Assume for this question...

Assume for this question that we are discussing a rare human disorder. Describe as detailed as possible the characteristics of this disorder if it is: autosomal dominant autosomal

Tools and techniques - effects of plant growth regulators, Tools and Techni...

Tools and Techniques - Effects of Plant Growth Regulators We have discussed about the "effect of auxins". In this section we shall discuss the methodology being followed in h

Illustrate the applications of gellan gum, Illustrate the Applications of G...

Illustrate the Applications of Gellan gum Gellan is a highly versatile food ingredient and has numerous applications in foods. The combination of gelatin with gellan, by compar

What are plasmids, What are plasmids? What is the importance of plasmids fo...

What are plasmids? What is the importance of plasmids for the recombinant DNA technology? Plasmids are circular fragments of DNA that are accessories to the major bacterial DNA

How to facilitate information transfer during transcription, How is energy ...

How is energy used to facilitate information transfer during transcription?

What is the meaning of oedema, What is the meaning of Oedema? In some p...

What is the meaning of Oedema? In some pathological conditions the body is in a positive water balance; that is the intake of fluids is greater than the excretion, and the pati

What is the most probable inheritance pattern of a trait, What is the most ...

What is the most probable inheritance pattern of a trait with gaussian proportional distribution of phenotypical forms? If a trait statistically has a normal (bell-shaped curve

Movement, Movement Movement is another characteristic of living things...

Movement Movement is another characteristic of living things. It does not always mean locomotion or movement from one place to another. In animals movement is quite obvious. W

Define the meaning of vital signs, Define the meaning of Vital signs V...

Define the meaning of Vital signs Vital signs are measures of different physiological statistics, often taken by health professionals, in order to assess the most basic body f

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