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

Osteoporasis, OSTEOPORASIS - Reduction in bone tissue mass causing weak...

OSTEOPORASIS - Reduction in bone tissue mass causing weakness of skeletal strength. It leads to crush fracture. It occurs in pastmenopausal women & elderly man. Common

Explain the management strategies congenital heart disease, Explain the Man...

Explain the Management Strategies for Adults with Congenital Heart Disease ? The goals for management of congenital heal disease in adults are improving upon the natural histo

Etiology of constipation, Q. Etiology of constipation? The etiology and...

Q. Etiology of constipation? The etiology and management of two distinct disorders of the bowel viz., diarrhoea and constipation. We small continue our discussion on certain ot

Sporozoans – protozoan, Sporozoans – Protozoan Sporozoans of the genus...

Sporozoans – Protozoan Sporozoans of the genus Plasmodium are responsible for causing a serious human disease, malaria. They are among, the best known parasites which live in

Describe about the secondary prevention - food allergy, Describe about the ...

Describe about the Secondary Prevention - Food Allergy? Secondary allergic preventive measures will focus on: Initiating prospective surveillance of infants, young child

Alcoholism, ALCOHOLISM - Continual heavy consuming of alcohol is cal...

ALCOHOLISM - Continual heavy consuming of alcohol is called alcoholism or drinking . Word alcohol is refered to C 2 H 5 OH or ethyl alcohol or ethanol or grain alcohol.

Physiology, using an example in each case,describe the three main feeding m...

using an example in each case,describe the three main feeding methods used by animals based on the type of food available

List disbeliefs which patients have about insulin, Q. List disbeliefs which...

Q. List disbeliefs which patients have about insulin? a) Insulin is not effective. Some patients believe that insulin is not effective for treating diabetes. b) Insulin c

The warmest parts of the body?, What are likely to be (a) the coldest, (b) ...

What are likely to be (a) the coldest, (b) the warmest parts of the body? The extremities of the body (hands and fingers, feet and toes, ears and nose) are likely to be the col

Regional specialisation, Regional Specialisation Regional specialisati...

Regional Specialisation Regional specialisation takes place usually by three processes – 1) Restriction of certain structures to a few segments, for example, gonads are res

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