The cells send their CO2 and other junk out to the venal end of the capillary exchange where the capillaries unite into venules, and then merge into veins that head back to the heart.

细胞将二氧化碳和其他垃圾输送到毛细血管交换的静脉端，毛细血管在那里结合成小静脉，然后合并成静脉返回心脏。