E. True Volume changes detected by vascular low-pressure receptors affect ADH secretion.

456. A. False It is produced by the alpha cells. B. True It is quite similar in structure to secretin. C. True It normally prevents a serious fall in blood glucose. D. False It is much shorter (5-10 minutes); this allows glucagon levels in the blood to

adjust rapidly to changes in blood glucose levels. E. True It also mobilizes fatty acids.