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

Best relates the severity and frequency of natural events, In general, whic...

In general, which of the following best relates the severity and frequency of natural events, such as storms or droughts? A) Nothing is known about this relationship. B) The severi

Points to keep in mind for diabetes counsellor, Counselling involves a proc...

Counselling involves a process, the aim of which is to help others to help themselves by making better choices and becoming better choosers of options. The counsellor's repertoire

Benefits and dangers using dna , Read the information found in the Bioethic...

Read the information found in the Bioethics: Choices for the Future box on page 40 of the text entitled "Should you Bank your Stem Cells?"  Based on the information given, discuss

Explain the gall bladder disease - effect of obesity, Explain the Gall blad...

Explain the Gall bladder disease - Effect of Obesity? Obesity is one of the risk factors for formation of gallstones. The super saturation of bile with cholesterol in obese ind

Explain creaming volume formulae - performance evaluation, Performance Eval...

Performance Evaluation Cake batter aeration can be affected by the plasticity, consistency, emulsification, bake stock formulation and other fats and oil properties.  Creamin

Define a ''rag doll'' seed tester, A 'rag doll' seed tester Fold a squa...

A 'rag doll' seed tester Fold a square metre of muslin twice in the similar direction. Near one end mark out eight or ten squares about 5 cm by 5cm with a pencil. Number the sq

What is eutrophication, What is eutrophication? Eutrophication is the p...

What is eutrophication? Eutrophication is the process of excessive enhancing of nutrients, like phosphate and nitrate, in water because of direct deposit of non treated sewage.

What is the charge on the tripeptide, Answer the following eight questions ...

Answer the following eight questions (a through h) based upon a tripeptide sequence of the following amino acids (one-letter codes are given): S (serine) P (proline) K (lysine)

Biomolecules, indicator for testing for the presence of sugar

indicator for testing for the presence of sugar

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