Adrenal gland Flashcards
What is produced in the zona glomerulosa?
mineralocorticoids
What is produced in the zona fasciculata?
glucocorticoids (a little bit of androgen as well)
What is produced in the zona reticularis
androgens
What is the order of the zones from the capsule to the medulla in the adrenal gland?
glomerulosa; fasciculata; reticularis
What regulates aldosterone?
renin-angiotensin system and plasma potassium
What is CRH?
corticotropin release hormone produced by the hypothalamus in response to illness; stress and time of day which stimulate ACTH release from the anterior pituitary
How does angiotensin II cause BP increase?
direct- vasoconstriction; indirect- aldosterone
What are the 6 classes of steroid receptors?
glucocorticoid; mineralocorticoid; progestin; oestrogen; androgen; vitamin D
What are the major actions of glucocorticoid on the CNS?
mood lability; euphoria/psychosis; decreased libido
What are the effects of cortisol on bone/connective tissue?
accelerates osteoporosis; decreases serum calcium; decreases collagen formation; decreases wound healing
What are the immunological effects that cortisol has?
decreased capillary dilatation/permeability; decreased macrophage actvitiy; inflammatory cytokine production
What are the metabolic effects of cortisol?
increases blood sugar; increased lipolysis; central redistribution; increased proteolysis
What are the circulatory/renal effects of cortisol?
increased cardiac output; increased BP; increased renal blood flow and GFR
Where is the mineralocorticoid receptor found?
kidneys; salivary glands; gut; sweat glands
What are the effects of aldosterone?
sodiumpotassium balance; BP regulation; rgulation of ECF
What are the causes of primary adrenal insufficiency?
Addison’s disease; congenital adrenal hperplasia; adrenal TB/malignancy
What are the causes of secondary adrenal insufficiency?
iatrogenic; pituitary/hypothalamic disorders
What happens in Addison’s disease?
AI destruction of adrenal cortex
What are the symptoms of Addison’s disease?
anorexia; wt loss; fatigue; dizziness and low BP; abdo pain; vomiting; diarrhoea; skin pigmentation
How is Addison’s diagnosed?
U&E- hyponatraemia; hyperkalaemia; short synacthen test; ACTH lvels; renin/aldosterone levels; autoantibodies
What is the treatment for adrenal insufficiency?
hydrocortisone as cortisol replacement; fludrocortisone and aldosterone replacement
What is the commonest cause of secondary adrenal insufficiency?
exogenous steroid use
What is the difference between secondary and primary adrenal insufficiency in terms of clinical features?
secondary- pale skin (no increased ACTH) and aldosterone production is intact
What are clinical features of cortisol excess?
easy bruising; facial plethora; striae; proximal myopathy