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Foetal Circulation - Anatomy & Physiology (view source)
Revision as of 14:58, 31 July 2008
, 14:58, 31 July 2008no edit summary
===Circulatory Changes at Birth===
===Circulatory Changes at Birth===
Important circulatory changes occur at birth due to the replacement of the placenta by the lungs as the organ of respiratory exchange. When an newly born animal takes its first breath, the lungs and pulmonary vessels expand thereby significantly lowering the resistance to blood flow. This subsequently lowers the pressure in the pulmonary artery and the right side of the heart. On the other hand the removal of the placenta courses an increase in the resistance of the systemic circulation and hence an increase in the pressure of the left side of the heart.
The birth of the animal also triggers the closure of the foetal shunts:
====Closure of the Ductus Venosus====