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

Skeleton, how they are joints to each other

how they are joints to each other

Explain the peripheral resistance, Explain the Peripheral Resistance Re...

Explain the Peripheral Resistance Resistance offered by arterioles or resistance vessels, as you have read above, is termed as peripheral resistance. Changes in peripheral resi

What does myeloid immunodeficiency cause, Myeloid immunodeficiency causes p...

Myeloid immunodeficiency causes phagocytic function, which is impaired. Those who are affected with this will undergo with enhance in susceptibility to bacterial infection.

#ti.., what would happen if there is no revolution?

what would happen if there is no revolution?

Describe the blood sugar testing, A small drop of blood is required to perf...

A small drop of blood is required to perform the test and this can be easily obtained from the patient's fingertip. A large number of glucometer devices are easily available and t

Chromosomes and molecular homology, CHROMOSOME S AND MOLECULAR HOMOLOGY - ...

CHROMOSOME S AND MOLECULAR HOMOLOGY - The DNA content of diploid cells is similar. Hoyer et al in 1965 showed that DNA of humans was 100% similar with chimpanzee and 94%

Locomotion in leech, LOCOMOTION IN LEECH - Leech moves by looping actio...

LOCOMOTION IN LEECH - Leech moves by looping action of its body on substratum. Posterior sucker is attached to base, body elongates, then anterior sucker is attached. Now po

Types of embryogeny, Types of Embryogeny On the basis of the plane of...

Types of Embryogeny On the basis of the plane of division of the zygote and of the cells of the 2-celled proembryo, and also taking into account the relative contributions of

The cell, how autophagy help in converting a tadpole larva into adult amphi...

how autophagy help in converting a tadpole larva into adult amphibian

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