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

Primitive arthropods, Primitive Arthropods The primitive arthropods, O...

Primitive Arthropods The primitive arthropods, Onychophora (for example Peripatus) have a series of paired legs which are not jointed but have a ringed appearance because of t

Explain leptospirosis, Leptospirosis It is a bacterial disease that oc...

Leptospirosis It is a bacterial disease that occurs in many domestic and wild animals, is endemic worldwide, but the highest incidence is in tropical and subtropical areas. Tr

Waste management in other species, W a s t e Management in other specie...

W a s t e Management in other species Solid and pellet nature of sheep and goat faecal matter make it easier to handle. This manure can easily be swept off the floors and d

Explain the transmission electron microscope, Explain the Transmission Elec...

Explain the Transmission Electron Microscope Here, thin and dehydrated specimen is used. Electrons pass through the specimen and form image on to photographic film. These are u

Getting ready to grow bacteria, Getting ready to grow bacteria Secure t...

Getting ready to grow bacteria Secure two or three dozen shallow glass dishes. The glass coasters used to stay bed castors from marring floors will do. Cut 5 cm squares of wind

Explain the anatomic variability of long buccal nerve, Anatomic variability...

Anatomic variability of long buccal nerve demands caution during surgery. Discuss Long buccal nerve, a branch of the mandibular division of trigeminal nerve emerges deep to the

Empirical validity of test procedures, Empirical validity of test procedure...

Empirical validity of test procedures Reitan's great concern has always been with the empirical validity of test procedures. Such validity can only be established by the collec

Neuroglia - organisation of nervous system, Neuroglia - Organisation of Ner...

Neuroglia - Organisation of Nervous System We may refer neuroglia as the connective tissue of the nervous system. It involves all elements of the nervous system other than ne

Define dark field microscope, Define Dark Field Microscope In this micr...

Define Dark Field Microscope In this microscope, condenser system is modified, so that only reflected and refracted light by specimen forms an image. Here, the object is bright

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