Editing Circulatory system (section)

====Pulmonary circulation====
{{Main|Pulmonary circulation}}
[[File:2119 Pulmonary Circuit.jpg|thumb|370px|right|The [[pulmonary circulation]] as it passes from the [[heart]]. Showing both the [[Pulmonary artery|pulmonary]] and [[Bronchial artery|bronchial arteries]].]]
The pulmonary circulation is the part of the circulatory system in which [[Deoxygenated blood|oxygen-depleted blood]] is pumped away from the heart, via the [[pulmonary artery]], to the [[lungs]] and returned, oxygenated, to the heart via the [[pulmonary vein]].

Oxygen-deprived blood from the superior and inferior [[vena cava]] enters the right atrium of the heart and flows through the [[tricuspid valve]] (right atrioventricular valve) into the right ventricle, from which it is then pumped through the [[pulmonary semilunar valve]] into the pulmonary artery to the lungs. [[Gas exchange]] occurs in the lungs, whereby {{CO2|link=yes}} is released from the blood, and oxygen is absorbed. The pulmonary vein returns the now oxygen-rich blood to the [[left atrium]].<ref name="Guyton"/>

A separate circuit from the systemic circulation, the [[bronchial circulation]] supplies blood to the tissue of the larger airways of the lung.