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 about fish epidermis, How different is the fish epidermis from the ...

How different is the fish epidermis from the amphibian epidermis? The fish epidermis is very thin and having mucus-secreting cells. The fish skin does not present keratin. The

Define body composition - geriatric nutrition, Define Body Composition - Ge...

Define Body Composition - Geriatric Nutrition? After 30 years of age 1-2% decline in lean body mass annually is observed. The total body water, bone mass and lean body mass

What are the intermediate hosts of plasmodium, What are the intermediate an...

What are the intermediate and the definitive hosts of the plasmodium? In the life cycle of the plasmodium humans are the middle hosts (where asexual reproduction takes place) a

Energy storage, Energy Storage As we said above, food intake and ener...

Energy Storage As we said above, food intake and energy expenditure for animals is approximately equal. If energy expenditure exceeds food intake, then the excess energy is t

What is the role of pharmacologic therapy, What is the role of pharmacologi...

What is the role of pharmacologic therapy in the treatment of peri implantitis. Pharmacological therapy for patients presenting with an ailing implant involves subgingival irri

Meroblastic or partial cleavage, Meroblastic or partial cleavage The e...

Meroblastic or partial cleavage The egg does not divide totally because divisions are restricted to only a part of the egg where as the rest of the egg remains completely uncl

What is the mechanism described by darwin, What is the mechanism described ...

What is the mechanism described by Darwin that eliminates species less adapted to environmental conditions? The mentioned mechanism is the natural selection.

Define effect of fat on quality and quantity of human milk, Define effect o...

Define effect of Fat on quality and quantity of human milk? Fat content of milk appears to be subject to variability as compared to other constituents. The average fat content

Why are the tropical forests also known as stratified forest, Why are the t...

Why are the tropical forests also known as stratified forests? In tropical forests tall trees of various species have their crowns forming a superior layer under which diverse

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