Respuesta :
The digestive system also works in parallel with your excretory system (kidneys and urination). While the digestive system collects and removes undigested solids, the excretory system filters compounds from the blood stream and collects them in urine.
Answer:
circulatory and respiratory
Explanation:
when blood heads to the heart for oxygen the blood gets sent out to the lungs through the pulmonary vein where the blood gets its oxygen and sent back to the heart using the pulmonary artery and sent out to the body using the aortas