Answer: Dilate blood vessels and promote sodium/water loss, thereby lowering blood pressure.
- A Increase renin secretion from the juxtaglomerular apparatus
- B Dilate blood vessels and promote sodium/water loss, thereby lowering blood pressure
- C Stimulate the adrenal medulla to release more adrenaline
- D Constrict blood vessels and promote sodium/water retention, raising blood pressure further
Correct answer: B. Dilate blood vessels and promote sodium/water loss, thereby lowering blood pressure
Explanation: ANF is released when the atrial wall is stretched by increased blood volume; it causes vasodilation and increased renal sodium/water excretion, lowering blood pressure.
The hypothalamus releases hormones that direct the pituitary, which releases its own trophic hormone to a target gland; that gland's hormone output then feeds back (dashed lines) to suppress both the pituitary and hypothalamus once levels are sufficient - a self-correcting loop running the entire endocrine system.
Concept context
The endocrine glands, hormone classification and mechanism of action, and negative feedback regulation.