Final answer:
The statement is true; the renal vein does drain into the lateral walls of the inferior vena cava, with the right renal vein entering directly and the left renal vein also receiving blood from the left adrenal vein.
Step-by-step explanation:
The statement that the renal vein drains into the lateral walls of the inferior vena cava is true. Blood supply from the kidneys is carried away from each kidney by the renal veins, which are normally the largest veins that enter the inferior vena cava. The right renal vein drains directly into the inferior vena cava, while the left renal vein, due to its longer length as it crosses the body, also receives blood from the left adrenal (or suprarenal) vein before emptying into the inferior vena cava.