Final answer:
Urine volume is indeed influenced by blood pressure, as the glomerular filtration rate is determined by systemic blood pressure. When blood pressure is normal, sufficient hydrostatic pressure enables proper filtration and urine production. The kidney can regulate its functioning across a wide range of blood pressures, helped by hormones that manage blood volume and pressure.
Step-by-step explanation:
Is Urine Volume Influenced by Blood Pressure?
True, urine volume is influenced by blood pressure. The glomerular filtration rate (GFR), which is a measure of the amount of blood being filtered by the kidneys, is indeed affected by hydrostatic pressure. This hydrostatic pressure is in turn determined by systemic blood pressure. When the blood pressure is normal, the hydrostatic pressure in the glomeruli is high enough to enable filtration. However, if blood pressure falls too low, it can reduce GFR, leading to a decrease in urine production because less fluid is filtered. The kidney's autoregulatory mechanism allows it to maintain normal function across a range of blood pressures using smooth muscle adjustments.
Furthermore, mechanisms like the renin-angiotensin-aldosterone system, as well as the release of antidiuretic hormone (ADH) and atrial natriuretic hormone (ANH), influence urine volume by modifying blood volume and blood pressure. These hormones can adjust blood pressure and also the concentration of sodium and water reabsorption, hence affecting urine output.