Final answer:
Increased release of ADH from the posterior pituitary gland leads to an increase in blood pressure. This is due to ADH causing vasoconstriction and promoting water reabsorption in the kidneys, which restores blood volume and raises blood pressure.
Step-by-step explanation:
The antidiuretic hormone (ADH), also known as vasopressin, is produced by the hypothalamus and released from the posterior pituitary gland. The central role of ADH is to manage the body's water balance by adjusting the amount of water that is excreted by the kidneys. When the body experiences a drop in blood volume or an increase in blood osmolarity, ADH secretion is increased. This leads to two key responses:
- ADH prompts the kidneys to reabsorb more water, reducing urine volume and preventing dehydration. This action is carried out by the insertion of aquaporins into the kidney tubules, which increases water reabsorption into the capillaries.
- ADH also causes vasoconstriction, which increases peripheral resistance and thereby elevates blood pressure.
Therefore, the correct answer to the question is: a) Increased blood pressure. Additionally, while ADH has a role in osmoregulation—impacting sodium (Na+) levels indirectly by influencing water balance—the primary effect being discussed here is on blood pressure.