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 changes is most likely to occur, A 42 year old woman decides to lose w...

A 42 year old woman decides to lose weight on a diet prescribed by an anorexic friend. She loses about 30 pounds in 45 days, but her serum potassium level falls to 2.1 mmol/L (norm

State about the latent squint disease, State about the Latent squint diseas...

State about the Latent squint disease Latent squint is seen commonly as exophoria in infancy and presbyopic age and esophoria in childhood. Hypermetropes can have esophoria and

Describe about acyanotic congenital heart disease, Describe about Acyanotic...

Describe about Acyanotic Congenital Heart Disease ? The following lesions will be discussed here: Left to right shunts: Atrial Septal Defect (ASD), Ventricular Septal Defect

What are the vessels that carry blood to the kidneys, Q. What are the vesse...

Q. What are the vessels that carry blood to the kidneys? Is this blood venous or arterial? The renal arteries are ramifications of the aorta and so the blood filtered by the ki

Instance of negative feedback of the homeostatic regulation, Q. What is an ...

Q. What is an instance of negative feedback of the homeostatic regulation? Negative feedback happens when the response to a given action generates an effect that inhibits that

Respiration , how many types of respiration are?define them also

how many types of respiration are?define them also

Root - plant water relation, Root - Plant Water Relation Root system i...

Root - Plant Water Relation Root system is directly related to the absorption of water and its growth under field conditions is very much influenced by soil. In dry land agric

Visceral larva migrans, Visceral larva migrans Visceral larva migrans,...

Visceral larva migrans Visceral larva migrans, also known as larval granulomatosis, is a clinical syndrome produced by the extra-intestinal migration of larval nematodes and i

Ribosome in the translation of one mrna molecule, Q. How many of the same p...

Q. How many of the same proteins are made at the same time by each ribosome in the translation of one mRNA molecule? How does successive protein production occur in translation?

Explain beginning and the end of the third interphase period, Q. What are t...

Q. What are the events that mark the beginning and the end of the third interphase period? What happens in the cell in this period? The third interphase period is the G2, It be

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