Final answer:
The higher the plasma concentration of aldosterone, the more efficiently the kidney will reabsorb sodium, leading to increased blood volume and blood pressure, while also causing the excretion of potassium.
Step-by-step explanation:
The higher the plasma concentration of aldosterone, the more efficiently the kidney will reabsorb sodium. Aldosterone is a hormone that is essential for the regulation of sodium and potassium in the body. It acts on the distal convoluted tubules and collecting ducts of the kidneys, stimulating the sodium-potassium pump which leads to the reabsorption of sodium into the bloodstream. Consequently, as sodium is reabsorbed, water also follows due to osmosis, leading to an increase in blood volume and blood pressure. Conversely, aldosterone causes the excretion of potassium, helping maintain electrolyte balance.