Flashcards in MEH - Adrenal Glands Deck (42)
What are steroid drugs used for?
Used to treat inflammatory disorders such as asthma, IBD, RA, etc.
What is Addison's disease?
Chronic adrenal insufficiency, usually caused by autoimmune response
What are the signs/symptoms of Addison's disease?
- postural hypotension
- weight loss
- increased skin pigmentation
Why does hyperpigmentation occur in Addison's?
- decreased cortisol means that negative feedback on the anterior pituitary is reduced
- this means that more POMC (building block) is required to form ACTH
- POMC makes both ACTH and MSH (which forms melanin), so to maintain ACTH levels, more MSH is made as a byproduct
What is an Addisonian crisis?
Life threatening emergency due to adrenal insufficiency caused by severe stress, infection, trauma, cold, abrupt withdrawal of steroids, salt deprivation etc
What are the symptoms of an Addisonian crisis?
Nausea, vomiting, pyrexia, hypotension, vascular collapse
What is the treatment for an Addisonian crisis?
Fluid replacement and cortisol
What are the androgens that are released from the zona reticularis?
DHEA and androstenedione
What do 20% of chromaffin cells in the adrenal medulla lack?
N-methyl transferase, meaning they secrete noradrenaline instead of adrenaline
Which GCPRs can adrenaline act on?
B1 and B2, a1 and a2
What are the effects of adrenaline on the heart, lungs and blood vessels?
Heart - increase heart rate and contractility (B1)
Lungs - bronchodilation (B2)
Blood vessels - vasoconstriction in skin and gut (a1) or vasodilation (B2) in skeletal muscle