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

Animal classification, Explain metachrosis in frogs? How it is different fr...

Explain metachrosis in frogs? How it is different from change of skin colour of chemleon?

Define nutritional requirements of fats and oils, Define Nutritional Requir...

Define Nutritional Requirements of Fats and Oils? As with the other macronutrients, we do compute requirements of visible fats too for all age groups and give guidelines for se

What factor cause the measurement to change, During gym class Sally noticed...

During gym class Sally noticed that her friend Melissa always ran faster than her. Sally knew that they exercised equally, so she wondered what could cause Melissa to run so fast.

Why are pteridophytes more common in humid places, Q. Why are pteridophytes...

Q. Why are pteridophytes more common in humid places? Pteridophytes are more common in humid places since they depend on water for their gametes to fecundate one another. In hu

Tisues, digram or mammalian testis

digram or mammalian testis

Explain apomictic embryos in citrus, Apomictic embryos in citrus arise from...

Apomictic embryos in citrus arise from: 1. Synergids 2. Maternal sporophytic tissue in ovule 3. Antipodal cells 4. Diploid egg Maternal sporophytic tissue in ovule

Digestive system in the phylum arthropoda, Q. What is the kind of digestive...

Q. What is the kind of digestive system present in beings of the phylum Arthropoda? Are these animals deuterostomes or protostomes? The digestive tube of arthropods is complete

Heat production, Heat Production In the Homeotherms heat production m...

Heat Production In the Homeotherms heat production must be elevated if the ambient temperature falls below the critical temperature. Although all metabolic processes result i

Are environmental phenotypical changes transmitted offspring, Are environme...

Are environmental phenotypical changes transmitted to the offspring? Changes caused on the phenotypes by the environment are not transmitted to the offspring unless their prima

What are the types of antigenic agents, Q. What are the types of antigenic ...

Q. What are the types of antigenic agents that may constitute vaccines? Vaccines can be constituted of dead agents of disease, of inactivated toxins, of inactivated agents of d

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