Question

1. What are the 2 main ways that hormones can interact with their target cells? Which chemical classes of hormones use each of the different mechanisms? Give an example of each type of hormone.

2. Hormones may interact with each other in one of 3 ways to alter body function. Describe each type of interaction and give an example of hormones involved in each one.

3. How do circulating hormones differ from paracrines & autocrines?

4. How does a portal system differ from other circulatory pathways? How does the hypophyseal portal system enhance communication between the hypothalamus and anterior pituitary gland? Can you think of any advantages associated with such an arrangement?

5. How does the hypothalamus communicate with the posterior pituitary gland?

6. Is the following statement true or false? Explain your answer with an example. “A given hormone generally has the same effect on different target tissues.”

7. Once a hormone is secreted, what stops its action and why is it important to do so?

8. Diabetes mellitus can be successfully treated with the hormone insulin extracted from a cow, pig, or sheep pancreas. Why do you suppose this is possible?

9. Carl is suffering from hypothyroidism (his thyroid gland does not produce enough thyroid hormone). How could his physician determine if the problem is due to dysfunction at the level of the hypothalamus and pituitary or at the level of the thyroid gland itself? Start by drawing the pathway that regulates the release of thyroid hormones.

10. How are different types of hormones transported in the blood (lipid vs. water soluble)?

11. For each of the following hormones indicate whether it is tropic, which endocrine structure secretes it, what its major targets are, and how its release is regulated. Antidiuretic hormone Glucagon Prolactin Thyroid-stimulating hormone Growth hormone T3 GHRH ACTH Cortisol FSH & LH PIH Oxytocin Aldosterone Insulin Epinephrine

12. Mr. Olson visited his doctor complaining that he is constantly thirsty and is “in the bathroom day and night” relieving his bladder. The doctor ordered blood and urine tests and ruled out diabetes mellitus. What other hormonal condition could be causing these symptoms? What gland/organ is/are involved?

13. Why should the hypothalamus be referred to as the master endocrine gland? What regulates its endocrine activities?

Answer 1