Sentence:  Our own studies in which bronchial artery pulmonary artery anastomoses were demonstrated , were accomplished by injecting the bronchial artery first with no pressure on the pulmonary artery or <WSD>vein</WSD> , and then by injecting the pulmonary artery and vein afterwards . 
Meaning of the word marked with <WSD> tags:  any of four veins that carry arterial blood from the lungs to the left atrium of the heart