The juxtaglomerular apparatus can be found within the kidneys. The juxtaglomerular apparatus helps to balance blood pressure. Glomeruli inside the kidney filter blood as part of the process of making urine.d. As blood volume rises, the juxtaglomerular apparatus reduces renin production. This keeps the blood pressure in balance. If there are errors with this system, blood pressure can get too high, or drop too low, depending on the nature of the problem.