16. The Endocrine System

Adrenocorticotropic hormone (ACTH) stimulates the release of:

(a) Thyroid hormones by the hypothalamus

(b) Gonadotropins by the adrenal glands

(c) Growth hormones by the hypothalamus

(d) Steroid hormones by the adrenal glands

A cell's hormonal sensitivities are determined by the:

(a) Chemical nature of the hormone

(b) Quantity of circulating hormone

(c) Shape of the hormone molecules

(d) Presence or absence of appropriate receptors

(e) Thickness of its plasma membrane

More than one choice may apply. In the hormone-signaling pathway represented in the figure,_________ is the first messenger, and _______is the second messenger that will signal a change in cell activity.

Explain what mechanism of hormone action is occurring in this image. How does it work? Give an example of a hormone that uses this mechanism.

What six hormones primarily affect growth?

Describe the chemical nature of hormones.

Define hormone.

Provide one example for each way endocrine glands are stimulated to release their hormones.

What four conditions cause the release of erythropoietin?

Which type of hormone receptor—plasma membrane bound or intracellular—would be expected to provide the most long-lived response to hormone binding and why?

In Type 2 diabetes, insulin levels are frequently normal, yet the target cells are less sensitive to the effects of insulin. This suggests that the target cells:

(a) Are impermeable to insulin

(b) May lack enough insulin receptors

(c) Cannot convert insulin to an active form

(d) Have adequate internal supplies of glucose

(e) Both b and c

Roger has been extremely thirsty. He drinks numerous glasses of water every day and urinates a great deal. Name two disorders that could produce these signs and symptoms. What test could a clinician perform to determine which disorder Roger has?