Final answer:
The medial border of the kidneys that receives the renal blood vessels is known as the renal hilum, which is the entry and exit point for various structures providing service to the kidneys.
Step-by-step explanation:
The medial border of the kidneys that receives the renal blood vessels is called the renal hilum. This is the entry and exit site for structures servicing the kidneys, such as vessels, nerves, lymphatics, and ureters. The renal hilum is the concave part of the kidney where these structures enter and exit, and it also features the emergence of the renal pelvis, which forms from the joining of the major and minor calyces.
The renal arteries and veins, as well as the ureters, are intricately connected at the renal hilum, with the arteries coming directly from the descending aorta and the veins returning cleansed blood to the inferior vena cava. The renal pelvis then funnels urine into the ureter leading to the urinary bladder.