Chapter 7

Thinking about the feedback control loop among TRH, TSH, and thyroid hormone, would you expect the concentration of TSH to be normal, above normal, or below normal in an animal whose diet is deficient in iodine (an element essential for synthesizing thyroid hormone)?

An animal displays symptoms of excess cortisol secretion. What factors could be measured in a blood sample to determine whether the condition is caused by a defect at the hypothalamic/anterior pituitary level or the adrenal cortex level?

Discuss the release of hypophysiotropic hormones from the hypothalamus.

Glucose homeostasis is altered in diabetes. Elaborate on the changes that result in chronic hyperglycemia?

Explain the effect of a lack of activated vitamin \(D\) (due to inadequate exposure to sunlight) on an animal. How then are animals maintained indoors for the duration of their lifetime without developing these abnormalities?