Typically, the accessory renal artery courses into the renal hilum to perfuse the upper or lower renal poles. They may also enter the renal parenchyma directly from the renal cortex (called a polar artery). Rarely, they may arise from the lower thoracic aorta, as well as from the lumbar and mesenteric arteries.
The chain rule can be used to find whether they are getting closer or further apart. For example, one can consider the kinematics problem where one vehicle is heading west toward an intersection at 80 miles per hour while another is heading north away from the intersection at 60 miles per hour.
Chain gang. A chain gang is a group of prisoners chained together to perform menial or physically challenging work as a form of punishment. Such punishment might include repairing buildings, building roads, or clearing land. This system existed primarily in the Southern United States, and by 1955 had been phased out nationwide, with Georgia the last state to abandon the practice. Chain gangs were reintroduced by a few states during the get tough on crime 1990s, with Alabama being the first state to revive them in 1995. The experiment ended after about one year in all states except Arizona, where in Maricopa County inmates can still volunteer for a chain gang to earn credit toward a high school diploma or avoid disciplinary lockdowns for rule infractions.