Final answer:
An increased GFR leads to increased urine production and decreased blood volume, influenced by various body regulatory mechanisms including blood pressure and hormonal control.
Step-by-step explanation:
An increased GFR (Glomerular Filtration Rate) results in a higher urine volume because more fluid is being filtered and excreted by the kidneys. This process typically leads to a decreased blood volume since the fluid that makes up urine comes from the blood plasma. The GFR is influenced by various factors, including hydrostatic pressure and colloid osmotic pressure, as well as systemic blood pressure, autoregulatory mechanisms, sympathetic nervous activity, and paracrine hormones. Important hormones like aldosterone play a role in adjusting urine volume and blood volume. When blood pressure decreases, renin is released, leading to the production of angiotensin II, which stimulates aldosterone secretion. Aldosterone increases sodium reabsorption, which also promotes water reabsorption, and can lead to increased blood pressure and volume. Conversely, decreased aldosterone secretion would result in less reabsorption, promoting urine formation and leading to increased urine volume and decreased blood volume.