Right ventricle to the lungs. The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. The blood here passes through capillaries adjacent to alveoli and becomes oxygenated as part of the process of respiration.
The pulmonary artery carries deoxygenated blood from the heart to the lungs. It is one of the only arteries (other than the umbilical arteries in the fetus) that carries deoxygenated blood. In the human heart, the pulmonary trunk (pulmonary artery or main pulmonary artery) begins at the base of the right ventricle. It is short and wide—approximately 5 centimetres (2.0 in) in length and 3 centimetres (1.2 in) in diameter. This is called the pulmonary circulation. From your pulmonic valve, blood travels to the pulmonary artery to tiny capillary vessels in the lungs. Here, oxygen travels from the tiny air sacs in the lungs, through the walls of the capillaries, into the blood. At the same time, carbon dioxide, a waste product of metabolism, passes from the blood into the air sacs.  Types of arteries and veins. There are two types of arteries in the body: Pulmonary and systemic. The pulmonary artery carries deoxygenated blood from the heart, to the lungs, for purification while the systemic arteries form a network of arteries that carry oxygenated blood from the heart to other parts of the body. Arteries carry oxygenated blood (with the exception of the pulmonary artery and umbilical artery). Veins carry deoxygenated blood (with the exception of pulmonary veins and umbilical vein). Arteries carry blood away from the heart. Pulmonary arteries transport blood that has a low oxygen content from the right ventricle to the lungs. Systemic arteries transport oxygenated blood from the left ventricle to the body tissues. One system, the pulmonary vessels, transports blood from the right ventricle to the lungs and back to the left atrium. The other system, the systemic vessels, carries blood from the left ventricle to the tissues in all parts of the body and then returns the blood to the right atrium. The pulmonary artery carries deoxygenated blood from the right ventricle to the lungs. The blood here passes through capillaries adjacent to alveoli and becomes oxygenated as part of the process of respiration. In contrast to the pulmonary arteries, the bronchial arteries supply nutrition to the lungs themselves. In the human heart, the pulmonary trunk (pulmonary artery or main pulmonary artery) begins at the base of the right ventricle. It is short and wide—approximately 5 centimetres (2.0 in) in length and 3 centimetres (1.2 in) in diameter. Arterial circulation is the part of your circulatory system that involves arteries, like the aorta and pulmonary arteries. Arteries are blood vessels that carry blood away from your heart. (The exception is the coronary arteries, which supply your heart muscle with oxygen-rich blood.). Venous circulation is the part of your circulatory system that involves veins, like the vena cavae and pulmonary veins. Veins are blood vessels that carry blood to your heart. Veins have thinner walls than arteries. Veins can widen as the amount of blood passing through them increases Capillaries. Capillaries, the smallest and most numerous of the blood vessels, form the connection between the vessels that carry blood away from the heart (arteries) and the vessels that return blood to the heart (veins). The primary function of capillaries is the exchange of materials between the blood and tissue cells. One system, the pulmonary vessels, transports blood from the right ventricle to the lungs and back to the left atrium. The other system, the systemic vessels, carries blood from the left ventricle to the tissues in all parts of the body and then returns the blood to the right atrium. Arteries (from Greek ἀρτηρία (artēria) , meaning windpipe, artery) are blood vessels that carry blood away from the heart. While most arteries carry oxygenated blood, there are two exceptions to this, the pulmonary and the umbilical arteries.  There are two types of blood vessels in the circulatory system of the body: arteries that carry oxygenated blood from the heart to various parts of the body and veins that carry blood towards the heart for purification. Arteries carry oxygenated blood (with the exception of the pulmonary artery and umbilical artery). Veins carry deoxygenated blood (with the exception of pulmonary veins and umbilical vein).
https://en.wikipedia.org/wiki/Pulmonary_artery http://my.clevelandclinic.org/services/heart/heart-blood-vessels/how-does-blood-flow-through-heart http://www.diffen.com/difference/Arteries_vs_Veins http://training.seer.cancer.gov/anatomy/cardiovascular/blood/classification.html https://en.wikipedia.org/wiki/Pulmonary_artery http://www.nhlbi.nih.gov/health/health-topics/topics/hhw/circulation http://training.seer.cancer.gov/anatomy/cardiovascular/blood/classification.html https://en.wikipedia.org/wiki/Arterial http://www.diffen.com/difference/Arteries_vs_Veins
where is the pulmonary artery capillaries