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

Nutrition support for myocardial infarction, Q. Nutrition Support for myoca...

Q. Nutrition Support for myocardial infarction patient? The nutrient requirements of a MI patient vary from time of getting hospitalized in an emergency to the time of getting

Nitrogen cycle, Nitrogen Cycle The nitrogen is an essential constituen...

Nitrogen Cycle The nitrogen is an essential constituent of protein - the building block of all living cells. It is also a major constituent of the atmosphere (79 per cent). Al

Concerning the number of hosts how are parasites classified, Q. Concerning ...

Q. Concerning the number of hosts how are parasites classified? The Parasites that require only one host are called as monoxenous parasites. The Parasites that need more than o

Lumpy skin disease, Lumpy skin disease The disease, reported from Suda...

Lumpy skin disease The disease, reported from Sudan in 1970 and Egypt in 1988, is caused by a member of the Capripox virus. It affects cattle and is restricted to African coun

Explain human fetal circulation and the adult circulation, Concerning the m...

Concerning the mixture of arterial with venous blood what is the difference between the human fetal circulation and the adult circulation? In the human fetal circulation there

Simple proteins, SIMPL E PROTEINS The proteins are made of amino acids...

SIMPL E PROTEINS The proteins are made of amino acids only. Additional chemicals are absent. These are of two types -    (i) Fibrous        (ii) Globular ( i )

Procedures for diagnosis - polymerase chain reaction (pcr), P o lymer...

P o lymerase chain reaction (PCR): The PCR technique enables the exponential amplification of nucleic acid sequences from any biological samples. In the last few ye

What is the function of vitamin e, Q. What is the function of vitamin E? In...

Q. What is the function of vitamin E? In which foods can it be found? Vitamin E is also known as tocopherol is a fat-soluble vitamin that participates as coenzyme in the respir

Respiration, lesson plan practical requirements

lesson plan practical requirements

Ozone layer and its depletion, About 90% of ozone of atmosphere resides in ...

About 90% of ozone of atmosphere resides in stratosphere (16 to 40 km) layer of atmosphere as ozone layer. It protects life on this planet from harmful U.V. radiations. In absence

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