Final answer:
Aldosterone directly causes reabsorption of sodium ions, leading to an increase in blood volume and pressure, while ADH primarily promotes the reabsorption of water, only indirectly affecting sodium concentrations. Therefore, the statement is false.
Step-by-step explanation:
The statement that both aldosterone and antidiuretic hormone (ADH) regulate body fluid by causing absorption of sodium is false. Aldosterone and ADH do play roles in regulating body fluids, but they have different primary functions. Aldosterone is a mineralocorticoid hormone that promotes the reabsorption of sodium ions (Na+) in the kidney, which leads to water retention and an increase in blood pressure. This process occurs in the distal tubule and collecting duct of the nephron in the kidneys.
On the other hand, ADH primarily helps to regulate water balance by stimulating the insertion of aquaporin water channels into cell membranes of the collecting ducts, promoting water reabsorption into the bloodstream. While ADH can indirectly lead to sodium conservation due to water reabsorption and dilution of body fluids, its direct action is on water balance, not sodium reabsorption.