HPA Axis Jeopardy

Hypothalamus

100

What are some stimuli that cause release of the hypothalamic hormone onto the AP? 

Circadian rhythm, stress, low glucose

200

What hormone is released from the hypothalamus onto the AP?

CRH 

300

From what nucleus in the hypothalamus is CRH released? 

Paraventricular Nucleus

400

For hormones of the Posterior Pituitary, hormones are (synthesized in/released by) the hypothalamus & go to the Posterior Pituitary where they have their action. Think of ADH for example.  

For hormones of the Anterior Pituitary, hormones are (synthesized in/ released by) the hypothalamus & act on the Anterior Pituitary. 

PP: Synthesized in 

AP: Released by 

500

From what nucleus do the Sympathetic NS fibers that act on the adrenal medulla originate? 

Posterior Nuclei 

Anterior Pituitary Category

100

What hormone of the HPA axis negatively feeds back on the AP and Hypothalamus? 

Cortisol

200

What hormone is released in response to CRH (from the hypothalamus) from the AP? 

ACTH

300

CRH from the hypothalamus exerts its effects on this cell type in the anterior pituitary? 

Corticotrophs

400

What happens to the level of ACTH in a normal patient if they are given a dexamethasone suppression test? 

The high dose steroid would decrease the level of ACTH. 

500

What is one short vs. long term effect of ACTH on target cells?

Short Term effects of ACTH are to transfer stored cholesterol to the mitochondria, stimulate cholesterol binding to CYP450, and stimulate Cholesterol Desmolase  

Long term effects of ACTH are stimulation of transcription of genes for CYP450, and upregulation of ACTH receptors

Adrenals

100

Cortex has 3 layers, which are ______, _______, _______ from outside to inside? 

ZG 

ZF 

ZR

200

In general (with a little blurring of the lines), the 3 regions in the adrenal cortex produce these 3 types of steroids respectively.... 

1. ZG--> Mineralocorticoids 

2. ZF--> Glucocorticoids 

3. ZR--> Adrenal Androgens 

300

What condition are we concerned about after surgical resection of a cortisol-producing tumor that the patient has become sensitized to? 

Addison's Disease 

400

The adrenals have to pick up this compound from the blood (in addition to ACTH) to be able to synthesize steroids. 

Cholesterol from LDL 

500

Detecting 17 ketosteroids refers to which two compounds? 

DHEA and Androstenedione 

They are weak adrenal androgens with ketone group rather than the OH found in testosterone/ estradiol. 

Cortisol & Steroids

100

All steroids are produced from this 27 C precursor? 

Cholesterol 

200

Name at least 5 of the 7 types of compounds that can synthesized from cholesterol? 

Glucocorticoids (Cortisol) 

Mineralocorticoids (Aldosterone) 

Androgens (Testosterone, Estrogen) 

Progesterone 

1, 25 dihydroxide CCF 

Thyroxine 

300

Cortisol is synthesized ____________ 

Cortisol most often diffuses through the cell membrane to reach the _________ where it has most of its actions. 

On demand 

Nucleus, DNA, genes, etc same idea with things that have to do with increased transcription 

400

ACTH directly stimulates the first step in steroid synthesis from cholesterol, which is catalyzed by what enzyme? 

Cholesterol Desmolase

500

What one C # (what position) has a OH group in cortisol that aldosterone does not have?  

17

Actions & Feedback

100

Cortisol is considered ___________ (characterized by gluconeogenesis, lipolysis, proteolysis) and Diabetogenic 

Catabolic 

200

One reason we were concerned about infection in our patient is that cortisol has this effect on the immune system?

Suppress 

300

Cortisol is considered to be the long term pathway associated with prolonged stress. The short pathway when stressors occur takes what route? 

Hypothalamus with sympathetic fibers to the adrenal medulla, where epinephrine and NE are released to directly cause the fight or flight response. 

400

The presence of an appropriately functioning feedback mechanism allows for distinguishing between a cortisol producing tumor and an ACTH producing tumor. How? 

Dexamethasone test 

If you give Dexamethasone (like cortisol) and there is an ACTH-producing tumor, ACTH will remain high and it will not work to feed back on the AP. 

If you give Dexamethasone (like cortisol) and there is a cortisol-producing tumor, ACTH will decrease due to the proper functioning of negative feedback. 

500

If there is a mutation in 21 hydroxylase or 11 hydroxylase, what will be the predominant steroid hormone that produced from cholesterol? 

Androgens