Results from lab tests reveal abnormally high endogenous hormone levels, and you suspect a possible tumor. What regions will you ask the MRI technician to focus on?

Question

 Cushing's syndrome causes weight gain, excessive sweating, and muscle weakness. It can result from either the production of abnormally high levels of cortisol by the body, or overuse of glucocorticosteroid drugs. You are an endocrinologist working with a Cushing's syndrome patient. She is on hormonal birth control pills and takes an occasional ibuprofen.

A.  hypothalamus, anterior pituitary, and adrenal cortex
B.   adrenal cortex only
C.   hypothalamus and posterior pituitary
D.  anterior and posterior pituitary

Clarify Question
What is the key concept addressed by the question?
What type of thinking is required?

Gather Content
What do you already know about cortisol? What other information is related to the question?

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?

Answer 1

A.  hypothalamus, anterior pituitary, and adrenal cortex

Clarify Question
What is the key concept addressed by the question?
        · What regions cause too much cortisol?
What type of thinking is required?
            o This is an analyze question because you have to examine each set of regions for MRI tests to see if it would be appropriate to find the potential tumor.

Gather Content
What do you already know about cortisol? What other information is related to the question?
        · As the question states, Cushing’s syndrome causes weight gain, excessive sweating, and muscle weakness and can be caused by high levels of cortisol. Adrenocorticotropic hormone (ACTH), produced by the anterior pituitary, stimulates the adrenal cortex to produce corticosteroid hormones including cortisol. These hormones are important in regulating glucose homeostasis and the body’s response to stress. ACTH is stimulated by corticotropin-releasing hormone (CRH) produced by the hypothalamus.

Choose Answer
Given what you now know, what information is most likely to produce the correct answer?
        · Cushing’s syndrome is produced by excess cortisol, which is produced by the adrenal cortex. The adrenal cortex is stimulated by ACTH, which is produced in the anterior pituitary. This hormone is stimulated by CRH, which is produced by the hypothalamus. If cortisol levels are extremely high, it could mean that there is a tumor any of these areas- the hypothalamus, anterior pituitary, or adrenal cortex.

Reflect on Process
Did your problem-solving process lead you to the correct answer? If not, where did the process break down or lead you astray? How can you revise your approach to produce a more desirable result?
       · Answering this question correctly depended upon evaluating each region as to its appropriateness in finding the cause of Cushing’s syndrome- potentially caused by a tumor. If you got the answer correct, great! If not, which answer did you choose? Did you get confused as to which regions produce cortisol, ACTH, and CRH. Did you forget that CRH releases ACTH? Since both CRH and ACTH regulate cortisol, then testing all three of the regions that produce them would be needed to find the potential tumor.