Pituitary Disorders II Flashcards
Explain HPA pathway in regards to CRH
Corticotropin releasing hormone (CRH) from hypothalamus will stimulate pituitary corticotroph cells to secrete ACTH and that affects the adrenal glands. In the cortex of the adrenal glands the ACTH signal is recieves and caused the adrenal gland to produce cortisol.
in Cushing’s, there is an Abnormal or excess amount of _____ that is circulating throughout our system
cortisol
Prolonged exposure to cortisol or exogenous steroids on the body can cause __.
Cushing’s
Cortisol is produced in the _____ in response to stress
Adrenal cortex
Typically we want cortisol because??
that is how we deal with stress to the body, hypoglycemia, metabolism, etc.
Cushing syndrome most common cause is _____.
exogenous
When Cushing syndrome is caused by exogenous, what does that mean?
- what we’ve given pt/ what they are taking. Most of the time it is prednisone, so if they are chronic steroid use they run the risk of developing Cushing syndrome.
Adrenal tumor is another cause of Cushing syndrome, explain this.
hypothalamus releases CRH to stimulate pituitary gland to secrete ACTH which goes to adrenals and stimulates the cells and the cortex in the adrenal glands to release cortisol. Cortisol will circulate and have negative feedback on pituitary gland and hypothalamus. If there is too much then there will be a negative feedback and those two glands will decrease the amount they are producing. There is no negative feedback on cortisol in the adrenal glands, so a lot of cortisol won’t tell adrenal glands to stop producing cortisol, so an adrenal tumor will release cortisol no matter how much ACTH is produced. This is an ACTH independent source- It doesn’t matter how much ACTH is out there, the tumor is going to do its own thing and release cortisol.
Explain ectopic tumor as cause for Cushing’s syndrome
- this is a tumor outside of HPA access, so there is no tumor in hypothalamus, pituitary, or adrenal gland. The tumor is somewhere else producing ACTH which will stimulate adrenal glands to release cortisol. No negative feedback mechanism with cortisol., cortisol won’t affect ectopic tumor.
Cushing disease is caused by?
a pituitary (most cases) or hypothalamus problem
The most common cause of Cushing disease is _____.
a pituitary tumor
MOST COMMON CAUSE OF CUSHING _____ IS PITUITARY TUMOR.
DISEASE
MOST COMMON CAUSE OF CUSHING _______ IS EXOGENOUS.
SYNDROME