Flashcards in Adrenal - Basic Science & Hyperfunction Deck (56)
What 3 things are produced in the adrenal cortex?
Glucocorticoids, mineralocorticoids and androgens
What is the main glucocorticoid hormone produced by the adrenal cortex?
What is the main mineralocorticoid hormone produced by the adrenal cortex?
What type of cells are found in the adrenal medulla?
What is produced by the adrenal medulla? Give two examples.
Catecholamines e.g. adrenaline and noradrenaline
The synthesis of all the corticosteroids in the adrenal cortex begins with what?
Which type of steroid hormone is produced in the zona glomerulosa of the adrenal cortex?
What regulates mineralocorticoid activity?
Angiotensin II (RAAS) and K+ level
Which type of steroid hormone is produced in the zona fasciculata of the adrenal cortex?
Which type of steroid hormone is produced in the zona reticularis of the adrenal cortex?
What regulates glucocorticoid activity?
What regulates androgen activity?
What hormone is released from the hypothalamus in the hypothalamic-pituitary-adrenal axis?
Corticotropin releasing hormone
What hormone is released from the pituitary gland in the hypothalamic-pituitary-adrenal axis?
RAAS is a major regulator of aldosterone production. It is activated in response to what?
Decreased blood pressure
What is the effect of aldosterone?
Increase sodium reabsorption, and increase hydrogen and potassium excretion
Are corticosteroid receptors intra or extracellular?
What is the name for the clinical state of chronic glucocorticoid excess?
When is cortisol usually at its highest and lowest levels in the normal circadian rhythm?
Usually lowest at midnight and highest upon waking
What is the most common cause of Cushing's syndrome?
Use of oral steroids
What is the most common endogenous cause of Cushing's syndrome?
Cushing's disease (ACTH secreting pituitary adenoma)
What are the two main ACTH dependent (high ACTH) causes of Cushing's syndrome?
Cushing's disease and ectopic ACTH production
What are the two main ACTH independent (low ACTH) causes of Cushing's syndrome?
Adrenal pathology (adenoma/hyperplasia) and iatrogenic steroid use
What effect does Cushing's syndrome have on blood pressure?
What effect does Cushing's syndrome have on blood glucose levels?
If individuals with Cushing's syndrome have an acid-base disorder, what is this most likely to be?
Hypokalaemic metabolic alkalosis
What is the first line screening test for Cushing's syndrome?
Overnight dexamethasone suppression test
In the overnight dexamethasone suppression test, 1mg of dexamethasone is given at midnight and a cortisol level is taken at 8am. If the individual has Cushing's syndrome, the cortisol level will be greater than what?
If an overnight dexamethasone suppression test is not suitable, what is another screening test that can be used for Cushing's syndrome?
24h urinary free cortisol