Lectures 16-20 Flashcards
What does the Zona Glomerulosa secrete?
mineralocorticoids
What does the Zona Fasciculata secrete?
Glucocorticoids
What does the Zona Reticularis secrete?
Androgens
What would the over-production of mineralocorticoids, glucocorticoids, and catecholamines cause?
Cushing’s syndrom
Conn’s syndrom
Phaeochromocyoma
What do GRE’s do?
Glucocorticoid response elements
act as transcription factors
How are Glucocorticoids normally transported?
protein bound (90% to corticosteroid binding globulin) 5% are bioavailable
How is the synthesis of glucocorticoids regulated?
Corticotropin releasing hormone, on a circadian frame.
What do mineralocorticoids do?
Control water and salt balance in the DCT
Facilitates myocardial collagen production
What regulates the release of mineralocorticoids?
Renin and water
What is the most abundant adrenal androgen?
Dehydroepiandosterone (DHEA)
What is the production of adrenal androgens regulated by?
ACTH (not FSH/LH)
What is significant about catecholamine receptors?
There are 3 (alphas 1,2, and 3)
They have different effects
What are the symptoms of Adrenal insufficiency
Anorexia
Fatigue
Gastrointestinal problems
How would you diagnose primary adrenal insufficiency?
low cortisol levels
How would you diagnose secondary adrenal insufficiency?
adrenal gland should still respond to the ACTH test (Short Synacthen test)
What is the cause of primary adrenal insufficiency?
autoimmune adrenalitis (Addison's disease)
What is the significance of the cortisone-cortisol shuffle clinically
hydro-cortisone is used to replace cortisol
cortisone acetate replaces cortisone, but it isnt preferred
What would you do if a patient has suspected adrenal insufficiency?
inject hydrocortisone immediately
WHat are the 4 main signs and symptoms of Cushing’s syndrome?
Purple striae
Muscle atrophy
osteoporosis
Bruising
How would Cushing’ syndrome be diagnosed?
The dexamethasone suppression test
What are the trends in obesity between twins?
Dizygotics are more likely to have a similar BMI than Monozygotics
What affects the levels of Leptin?
An increase in food expenditure and decrease in energy expenditure will increase the secretion of leptin by adipose tissue
This will decrease appetite
What might Leptin defficiecny cause?
obesity
What would a greater % central abdominal fat correlate to?
A decrease in insulin sensitivity