Pulmonary circulation


Pulmonary circulation


            The pulmonary blood circulation starts from the right ventricle of the heart by the pulmonary trunk. The pulmonary trunk gets divided into the left and right pulmonary arteries on level of fifth thoracic vertebrae which reach into left and right lungs respectively. Here, these march further with bronchi by getting divided into arterioles. Further, they reach till the heads of bronchioles by getting dividing into minute capillaries. Here gases are interchanged consequently the deoxegenated blood changes into pure blood. The pure blood is gathered by the venules and they make four big veins. Among them, two veins from the right lung and two veins from the left lungs emerge out by taking oxegated blood and supply into left atrium through the different orifices. These four veins are called pulmonary veins. These are veins which only oxegated blood.  Supply of blood into the lungs is completed by the pulmonary circulation. The conduits supply deoxygenated blood from heart to lungs and bring it in the heart again. From this place, the oxygenated blood is supplied into the body. Pulmonary circulation takes 4 to 8 second in completion.