Lecture 9.2 summaries Flashcards
(Not highlighted, just a recap):
Describe the HP axis
1) Hypothalamus releases stimulating hormone to anterior pituitary
2) The pituitary gland releases its hormone which lands on effector organ
3) The organ performs its desired function, with may be additional hormone release or some specific function of said organ
-Typically, at each stage of the process, the product inhibits all steps that come before it
Describe the thyroid axis
Hypothalamus releases TRH
Thyrotropes release TSH
Thyroid releases T3/T4
This fuels cellular metabolism
-Normal Feedback: TSH negatively feeds back against TRH; T3/T4 negatively feeds back against the pituitary and hypothalamus
Corticotrope Pathway
Hypothalamus releases corticotropin releasing hormone
Ant. Pituitary releases adrenocorticotropic hormone
Adrenals release cortisol
Gonadotrope Pathway
Hypothalamus releases Gonadotropin Releasing Hormone
Ant. Pituitary releases follicle stimulating hormone and Luteinizing Hormone
Gonads release end products
Sexual development
Ant. Pituitary Tumors: Describe their distinct tissue types
1) Post. pituitary is neural tissue; therefore, cells do not proliferate, and tumors are rare
2) Ant. pit is endocrine tissue: This tissue type has a unique genetic predisposition for tumor formation that is not premalignant
List the 2 common cell types for anterior pituitary tumors
1) Lactotrophs
Somatotrophs
Under normal function hypothalamus stimulates somatotrophs with the release of growth hormone releasing hormone and inhibits them with release of what?
2) Somatotrophs release ______________
The liver releases _________
1) Somatostatin
Somatotrophs release growth hormone
The liver releases IGF-1
List the rule of 10s for Pheochromocytoma
10% extra-adrenal
10% bilateral
10% malignant
10% NOT associated w/ HTN
Of the 90% with HTN , 2/3 have paroxysmal episodes of sudden sever HTN and palpitations (can be fatal)
What are the 2 main causes of hypothyroid?
1) Iatrogenic (removed or ablated)
2) Thyroiditis (ex: Hashimoto’s)
