Endocrine 3

Question 1

2 areas of adrenals?

Answer 1

inner medulla (neural crest origin)
outer cortex (more glandular)

Question 2

3 zones of cortex?

Answer 2

glomerulosa
fasciculata
reticularis

Question 3

what for glomerulosa make?

Answer 3

aldosterone (mineralocorticoids)

Question 4

what does fasciulata make?

Answer 4

glucocorticoids (eg cortisol)

Question 5

what does reticularis make?

Answer 5

androgens

Question 6

what does medulla make?

Answer 6

adrenaline

noradrenaline

Question 7

where are most androgens made, what does this mean?

Answer 7

gonads

so adrenal problems foesnt really affect androgen function

Question 8

what are cortex products derived from?

Answer 8

cholesterol

Question 9

fasciculata hormones feed back to where?

Answer 9

pituitary (ACTH production)

Question 10

where does glomerulosa hormones feed back to?

Answer 10

RAAS system (kidney??)

Question 11

pathology causing lack of cortex hormones?

Answer 11

addisons disease (primary adrenal failure)
tumours (metastatic lung malignancy commonly)
TB
adrenal haemorrhage
haemochromatosis

Question 12

what happens in addisons disease?

Answer 12

autoimmune destruction of all 3 zones of adrenal cortex

Question 13

addisons phenotype?

Answer 13

pigmentation 
hair loss
weight loss (cortisol is an anabolic hormone)
postural hypotension
hypoglycaemia 
diarrhoea 
lethargy

Question 14

why does pigmentation occur in addisons?

Answer 14

pituitary produces ACTH to try and correct lack of cortisol from adrenals which also produces MSH as same pre-cursor

Question 15

aldosterone function?

Answer 15

maintain high enough blood pressure by increasing reabsorption of sodium
causes potassium loss (sodium potassium pump)

Question 16

addisons biochemistry?

Answer 16

hyponatraemia
hyperkalaemia
hypoglycaemia

Question 17

addisons diagnosis (dynamic testing)?

Answer 17

synACTHen test
synthetic ACTH given at 0 mins, should cause a rise in cortisol to >550 at 1 hr
measure ACTH at time 0, in primary adrenal problem it will be eelvated or inappropriately normal

Question 18

imaging in addisons?

Answer 18

CT

Question 19

replacement in addisons?

Answer 19

hydrocortisone (20mg split into 3 times through day)

fludrocortisone (once daily)

Question 20

main adrenal hormones which can be in excess?

Answer 20

aldosterone
cortisol
catecholamines

Question 21

adrenal hormone deficiency usually affects all hormones, excess usually affects only one at a time, T/F?

Answer 21

true

Question 22

Summarise RAAS?

Answer 22

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Question 23

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Answer 23

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Question 24

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Answer 24

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Question 25

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Answer 25

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Question 26

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Answer 26

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Question 27

what is conns syndrome?

Answer 27

aldosterone excess (due to adenoma)

Question 28

conns phenotype?

Answer 28

hypertension (aldosterone doesnt stop when BP is adequete so RAAS never switched off)

Question 29

conns biochemistry?

Answer 29

hypokalaemia (K+ removed in exchange for Na+) | dont get hypernatraemia as water follows the Na+ so its normal concentration

Question 30

how is conns confirmed?

Answer 30

aldosterone:renin ratio (aldosterone will be high and low renin) (body trying to stop production by stopping renin)

Question 31

how can conns be confirmed with dynamic testing?

Answer 31

give lots of Na+ (generally given 2L of NaCl to drink in clinic) which will suppress RAAS in normal people but not in conns

Question 32

imaging in conns?

Answer 32

CT

Question 33

conns management?

Answer 33

surgery to remove adenoma | spironolactone - aldosterone antagonist (can cause gynaecomastia)

Question 34

adrenal cushings biochem?

Answer 34

dexamethasone suppression test would give a low ACTH as its not a pituitary problem

Question 35

adrenal cushings?

Answer 35

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Question 36

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Answer 36

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Question 37

what drug can be used in cushings if not fit for surgery?

Answer 37

mityrapone??

Question 38

excess catecholamines (medulla hormones?

Answer 38

phaeochromocytoma (tumour involving chromaffin cells in adrenal medulla)

Question 39

phaeochromocytoma phenotype?

Answer 39

headache hypertension (episodic, sometimes hypotension, postural hypotension is common) palpitations sweating

Question 40

phaeochromocytoma testing?

Answer 40

24 hr urinary metanephrines (breakdown products of adrenaline/noradrenaline)

Question 41

how are catecholamines made?

Answer 41

synthesised from amino acid tyrosine

Question 42

how is phaeochromocytoma managed?

Answer 42

surgery | need to give alpha blockers then beta blockers for 6 weeks before surgery with rehydration

Question 43

why must you alpha block first?

Answer 43

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Question 44

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Answer 44

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Question 45

imaging in phaeochromocytoma?

Answer 45

CT

Question 46

10% rule in phaeochromocytoma?

Answer 46

10% are bilateral 10% are malignant 10% are genetic 10% are extra-adrenal

Question 47

nuclear medicine scan in phaeochromocytoma?

Answer 47

can tell whether functionally active and can look for metastases uses adrenaline precursor MIBG