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Flashcards in Endocrine - basic principles Deck (8)
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1
Q

Go over the thyroid axis

A
2
Q

Why are thyroid hormones of limited value in acutely unwell patients ?

A
  • Euthyroid sick syndrome often seen in starvation, critical illness or patients in intensive care unit.
  • Characterised by low free hormone levels and inappropriate low/normal TSH but the thyroid gland does not appear to be dysfunctional
3
Q

Go over the hypothalmic pituitary adrenal axis

A
4
Q

What is prolactin secreted by ?

A

Lactotroph cells of the anterior pituitary

5
Q

What are some of the problems you can have with cortisol secretion ?

A

Cortisol deficiency = adrenal insufficiency due to:

  • Primary adrenal failure (e.g. Addison’s disease)
  • Pituitary disease

Cortisol excess = Cushing’s syndrome due to:

  • Pituitary origin
  • Adrenal origin
  • Ectopic ACTH (exogenous steroids)
6
Q

What is the idea of dynamic testing done to assess hormone secretion/deficiency ?

A
  • Hormone excess – suppression test
  • Hormone deficiency – stimulation test
7
Q

What dynamic tests are done to assess cortisol excess or cortisol insufficiency ?

A
  • Stimulation test – Synacthen Test
  • Suppression test – Dexamethasone suppression test
8
Q

How is cushings syndrome diagnosed ?

A

Low dose dexamethasone suppression test:

  • Failure to suppress = Cushing’s syndrome