Decreased blood calcium level would result in increased (a) secretion of calcitonin, (b) secretion of PTH, (c) elimination of calcium by the kidneys, (d) osteoclast activity, (e) excitability of neural membranes.

What four cell populations make up the endocrine pancreas? Which hormone does each type of cell produce?

What effects does parathyroid hormone have on blood calcium level?

Julie is pregnant but is not receiving prenatal care. She has a poor diet consisting mostly of fast food. She drinks no milk, preferring colas instead. How would this situation affect Julie's parathyroid hormone level?

Aaron, a 42-year-old single father, goes to his physician complaining of nausea and chronic fatigue. He reports having felt fatigued and listless for about half a year, but he had attributed this to stress. He has lost considerable weight and, strangely, his skin looks tanned, even though he spends long hours at work and rarely ventures outside. His doctor finds very low blood pressure and a rapid, weak pulse. Blood tests show that Aaron does not have anemia, but his plasma glucose, cortisol, and Na⁺ are low, and his plasma K⁺ is high. His doctor orders an ACTH stimulation test, in which Aaron's secretion of cortisol is measured after he is given a synthetic form of ACTH. (a) What would account for Aaron's low plasma Na⁺ and high plasma K⁺ ? (b) What is the reason for doing an ACTH stimulation test? (c) Which gland is primarily affected if ACTH does not cause a normal elevation of cortisol secretion? What is this abnormality called? (d) Which gland is primarily affected if ACTH does cause an elevation of cortisol secretion?

Endemic goiter is not really the result of a malfunctioning thyroid gland. What does cause it?