Answer the following question given this paragraph: 

Systemic circulation is the longer loop of the cardiovascular system. It carries blood between the heart and the rest of the body. Oxygen-rich blood flows from the heart to cells throughout the body. As it passes cells, the blood releases oxygen and absorbs carbon dioxide. Then the oxygen-poor blood returns to the heart.


Q: In the cardiovascular system, where is the ultimate destination of the oxygen-poor blood?


A:
heart