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

Life cycle of malarial parasite, Life cycle of malarial parasite Whe...

Life cycle of malarial parasite When the mosquito sucks the blood, gametocytes enter its digestive system. They migrate into the walls of the digestive system and undergo

Define estimation of nitrogen and protein content, Estimation of Nitrogen a...

Estimation of Nitrogen and Protein Content Using Micro Kjeldahl's Method? Standardization of H 2 SO 4 Prepare a solution of 0.1 N H 2 SO 4  by diluting 2.8 ml of the con

Explain about the zone electrophoresis, Explain about the Zone Electrophore...

Explain about the Zone Electrophoresis? Zone electrophoresis which was introduced about a decade later describes the migration of charged macromolecules in a porous supporting

Goal of bcc programme, The overall goal of BCC programs for diabetes mellit...

The overall goal of BCC programs for diabetes mellitus is to promote behaviors that control diabetes mellitus and prevent complications. These include: Following treatment

Perception of light - floral induction, Perception of Light - Floral Induct...

Perception of Light - Floral Induction Stimulus Leaves are found to be organs that perceive light 'stimulus', K.C. Hamner and J. Bonner showed in 1938 that even if all the lea

Can you define a nutrient, Q. What is a nutrient? A nutrient is every s...

Q. What is a nutrient? A nutrient is every substance used in the metabolism and which is obtaining from the diet. For example, essential amino acids and vitamins are nutrients.

How proteins can be classified, How Proteins can be Classified? I. Shap...

How Proteins can be Classified? I. Shape and size: fibrous proteins and globular proteins. Fibrous proteins play structural roles  in organisms. Globular proteins consist of lo

What are diastolic compressive forces, Q. What are Diastolic Compressive Fo...

Q. What are Diastolic Compressive Forces? Coronary perfusion pressure equal to pressure gradient between the coronary arteries and the pressure in LV in diastole. When coronary

What is light microscope, Question Write a short note on the followin...

Question Write a short note on the following - 1 Plastids 2 Phagocytosis 3 Ribosomal subunits 4 Microfilaments 5 Cell cycle control 6 Tight junctions 7 W

What is the kind of digestion occurs in cnidarians, Q. What is the kind of ...

Q. What is the kind of digestion that occurs in cnidarians? These animals have a digestive cavity and they make intracellular and extracellular digestion. The extracellular dig

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