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

Discuss in short about soil, Discuss in short about soil " The collecti...

Discuss in short about soil " The collection of  natural bodies in the Earth's surface, in places modified or even made by man of Earthy materials, containing living matter  an

Explain how is cancer related to ras, Can someone explain how is cancer rel...

Can someone explain how is cancer related to ras and p53 gene? I know that the ras protein regulate cell growth and its mutation will cause cancer. How is the mutation caused?

Cellular machinery for the replication of nucleic acids, Which of the follo...

Which of the following statements is true? Answer Viruses are distict from cells by the absence of a lipid membrane around them. Viruses are parasites that require the cell's metab

A common biocontrol agent for the control of plant diseases, A common bioco...

A common biocontrol agent for the control of plant diseases is : 1. Baculovirus 2. Bacillus thuringiensis 3. Glomus 4. Trichoderma Trichoderma

Define how the sticky ends are formed and get joined, a) A recombinant DNA ...

a) A recombinant DNA is formed when sticky ends of vector DNA and foreign DNA join. b) Define how the sticky ends are formed and get joined.

Aspergillosis, Aspergillosis Aspergillosis is the most common chronic,...

Aspergillosis Aspergillosis is the most common chronic, granulomatous, necrotizing and cavitary disease of lungs, and is characterized by formation of white yellowish caseous

Explain how a water molecule is produced, Explain how a water molecule is p...

Explain how a water molecule is produced when glucose and fructose undergo a condensation reaction. The glucose molecule releases a hydroxide ion, OH -, and the fructose molec

Human heart is partially non-functional, If due to some injury the chordae ...

If due to some injury the chordae tendinae of the tricuspid valve of the human heart is partially non-functional, what will be the immediate effect? 1. The flow of blood into t

Gumbout chiton, what is the classification of the Gumbout Chiton?

what is the classification of the Gumbout Chiton?

What are differentiations of the cell membrane, What are differentiations o...

What are differentiations of the cell membrane? In some types of cells, the cell membrane presents differentiations that are essential for the specific functions of the cells.

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