DRAW IT In mammals, milk production by mammary glands is controlled by prolactin and prolactin-releasing hormone. Draw a simple sketch of this pathway, including glands, tissues, hormones, routes for hormone movement, and effects.

Why is the observation that one hormone may bind to more than one type of receptor important?

The relationship between the insect hormones ecdysteroid and PTTH is an example ofa. an interaction of the endocrine and nervous systems.b. homeostasis achieved by positive feedback.c. homeostasis maintained by antagonistic hormones.d. competitive inhibition of a hormone receptor.

If a person has a pituitary tumor that is oversecreting TSH, would this person be likely to have goiter as a symptom? Explain.

Compare and contrast the structure and function of the anterior and posterior pituitary glands.

Which two of the hormones listed below act upon the body with similar functions? Explain. a. glucagon b. oxytocin c. glucocorticoids d. ADH

Design a study to test the hypothesis that the symptoms of jet lag are caused by disruption of normal daily cortisol rhythms.

A strain of mice remains healthy as long as they are fed regularly. After they eat, their blood glucose level rises slightly and then declines to a homeostatic level. However, when these mice fast or exercise, their blood glucose drops dangerously. Which hypothesis best explains their problem? (Explain your choice.) a. The mice have insulin-dependent diabetes. b. The mice lack insulin receptors on their cells. c. The mice lack glucagon receptors on their cells. d. The mice cannot synthesize glycogen from glucose.

Suppose that during a detailed anatomical study of a marine invertebrate, you found a small, previously undescribed structure. How would you test the hypothesis that the structure is a gland that releases one or more hormones?