Endo 7 - Hypoadrenal disorders Flashcards
What is the ultimate precursor for all steroids?
Cholesterol
Outermost to innermost, what are the layers of the adrenal cortex and what do they produce?
Outer = z. glomerulosa = mineralocorticoid (aldosterone)
Middle = z. fasciculata = glucocorticoid
Inner = z. reticular = estradiol
What are the causes of adrenocortical failure?
- TB - tuberculous Addisons disease (commonest worldwide)
- Autoimmune Addisons disease (commonest UK)
- Congenital adrenal hyperplasia
What are the symptoms of Addisons disease?
- Tired, exhaustion
- Pigmentation
- Hypotension
What are the consequences of adrenocortical failure?
- Fall in BP
- Loss of salt in urine
- Increased plasma potassium
- Fall in glucose due to glucocorticoid deficiency
- High ACTH - increased pigmentation because ACTH also stimulates MSH
What pro hormone is broken into MSH and ACTH
POMC
What are some tests and results that indicate Addisons disease?
9AM cortisol - LOW
ACTH - HIGH
What is a short synACTHen test
250 micrograms of synacthen given IM
If cortisol levels rise to normal, then they don’t have Addisons
What is the commonest cause of Congenital adrenal hyperplasia?
21-hydroxylase deficiency
can be complete/partial
What hormones are deficient in complete congenital adrenal hyperplasia?
Aldosterone and cortisol
less than 24 hrs survival
Which hormones are in excess in complete congenial adrenal hyperplasia
Sex steroids and testosterone particularly
Describe the presentation of congenital adrenal hyperplasia
- presents as a neonate with a “salt losing Addisonian crisis”
- Girls may have ambiguous genitalia (civilised by adrenal testosterone)
Which hormones are deficient in partial congenital adrenal hyperplasia?
Aldosterone and cortisol
Which hormones are in excess in partial congenital adrenal hyperplasia?
Sex steroids and testosterone
What is the main problem of partial 21 hydroxylase deficiency?
In later life - hirsutism and virilisation in girls
Precocious puberty in boys die to adrenal testosterone
Deficiency of 11 hydroxylase enzyme can cause what?
Excess deoxycorticosterone - which behaves like aldosterone
Can cause hypertension and hypokalaemia
Which hormones are deficient in 11-hydroxylase deficiency?
Cortisol and aldosterone
Which hormones are in excess in 11-hydroxylase deficiency?
Sex steroids and testosterone and 11-deoxycorticosterone
What are the problems with 11-hydroxylase deficiency?
Virilisation, hypertension, hypokalaemia
Which 3 genetic causes can cause congenital adrenal hyperplasia
21 hydroxylase deficiency, 11 hydroxylase deficiency, 17 hydroxylase deficiency
Which hormones are in excess in 17 hydroxylase deficiency?
Cortisol and sex steroids
Which hormones are in excess in 17 hydroxylase deficiency?
11-deoxycorticosterone and aldosterone
What are problems associated with 17 hydroxylase deficiency?
Hypertension, low K, no puberty/sex steroids, glucocorticoid deficiency
