Lecture 2 - endocrinology (part 2 of 6) We know from physiology that the body s use of calcium in all of it s cells is more important than keeping the calcium in the bones. So maintaining calcium in circulation and its accessibility to the cells in the body is extremely physiologically important - it s maintained at a very narrow range under normal physiological conditions. And of course, the gut is where dietary calcium (cheese, eggs, milk etc. ) is absorbed: under the in uence of parathyroid hormone and downstream events circulating levels of calcium rise. Glucocorticoid production: showing this example because it s the hp-end organ axis. Acth at the level of the hypothalamus and the pituitary. The following sections (on the different endocrine glands - today we ll look at the pituitary gland and the thyroid gland) will be structured like this: *aside: summary of what we will go through in the next few lectures.