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

Define the concept of food security, Define the Understanding the Concept o...

Define the Understanding the Concept of Food Security? Food security may be defined as a physical and economic access by all people, at all times, to sufficient food to meet th

Describe about the lysosomes enzymes, Describe about the Lysosomes enzymes ...

Describe about the Lysosomes enzymes Within the cytoplasm of the cell, several hydrolytic enzymes (lytic enzymes) capable of hydrolysing proteins, nucleic acids and carbohydra

What are multiple alleles, What are multiple alleles? Is there dominance in...

What are multiple alleles? Is there dominance in multiple alleles? Multiple alleles is the phenomenon in which the similar gene has more than two dissimilar alleles (in normal

What is circulation, What is circulation? Circulation is the movement o...

What is circulation? Circulation is the movement of substances as nutrients and gases within blood vessels and cavities all by the organism.

Define the needs for enteral feeding, Define the needs for Enteral Feeding?...

Define the needs for Enteral Feeding? For enteral feeding following need to be considered: - In preterm calorie density to be 0.8 Kcal/ml, - LBW formulas used: protein -

Evolution of dental implants, The first evidence of implants dates back to ...

The first evidence of implants dates back to 600 A.D. in the Mayan population. There are reports that the ancient Egyptians attempted intra-osseous implantation of animal teeth or

Examine six bad listening habits, Discuss six bad listening habits. Which d...

Discuss six bad listening habits. Which do you think is the biggest challenge for you personally?

Morphology, Condensed which is specialised to take part in sexual reproduct...

Condensed which is specialised to take part in sexual reproduction of angiosperm is called

Effect of alcoholic beverage, Q. Why does the urinary volume increase when ...

Q. Why does the urinary volume increase when alcoholic beverages are ingested? Alcohol inhibits the ADH (antidiuretic hormone) secretion by the hypophysis and Low ADH reduces t

Define the term parasites, Normal 0 false false false E...

Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4

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