Which hormones help regulate blood pressure and volume? (A) ADH and ANH (C) ADH and PTH (D) All apply.

To regulate blood pressure and blood volume, several hormones play crucial roles. Here's a breakdown of the options provided: 1. **ADH (Antidiuretic Hormone)**: - **Function**: ADH, also known as vasopressin, promotes water reabsorption in the kidneys. By conserving water, it increases blood volume and, consequently, blood pressure. 2. **ANH (Atrial Natriuretic Hormone)**: - **Function**: ANH is released by the heart's atria in response to increased blood volume. It promotes the excretion of sodium and water by the kidneys, reducing blood volume and lowering blood pressure. 3. **PTH (Parathyroid Hormone)**: - **Function**: PTH primarily regulates calcium and phosphate levels in the blood. It doesn't have a direct role in controlling blood pressure or blood volume. Given the roles of these hormones: - **Option (A) ADH and ANH**: Both hormones directly regulate blood pressure and volume. - **Option (C) ADH and PTH**: PTH is not involved in blood pressure regulation. - **Option (D) All apply**: Since PTH isn't directly related to blood pressure and volume regulation, this option is incorrect. **Correct Answer:** **(A) ADH and ANH**