Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Endocrinology > Adrenals > Flashcards

Adrenals Flashcards

(65 cards)

Start Studying
1
Q

What are the 3 zones of the adrenals and what do they produce?

A

GFR
Gets sweeter as you go deeper

Outer zone - zona glomerulus - produces aldosterone

Middle zone - zona fasiculata - produces cortisol

Inner zone - zone reticularis - produces sex steroids

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Adrenal hormones are derived from …

A

Cholesterol

ACTH activates enzyme that converts cholesterol to pregnenolone –> aldosterone, cortisol, testosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Low aldosterone results in …

A

Lose Na+, lose water, hold onto K+ , hold onto hydrogen ions
= Hypovolaemia, hypotension, metabolic acidosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Low cortisol results in …

A

Life threatening hypotension

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What happens in CAH i.e. 21-hydroxylase deficiency?

A

21-hydroxylase deficiency –> defective conversion from 17-OHP to 11-deoxycortisol –> high 17-OHP –> high testosterone (shunt production towards testosterone)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

How to diagnose CAH i.e. 21-hydroxylase deficiency?

A

High serum 17-OHP (screening test for suspected CAH)

ACTH stimulation test is gold standard confirmatory test
Give ACTH –> further rise in 17-OHP

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What’s the difference between Classic adrenal hyperplasia and Non-classic adrenal hyperplasia?

A

Both are due to 21-hydroxylase deficiency

Classic adrenal hyperplasia

  • More severe form
  • 0% 21-hydroxylase activity –> 0 aldosterone and cortisol production. All production shunted towards testosterone.
  • Present in infancy with adrenal insufficiency and salt wasting. Females have ambiguous genitalia.

Non-classic adrenal hyperplasia

  • Less severe form and more common
  • 50% 21-hydroxylase activity –> reduced aldosterone and cortisol production and high testosterone
  • No salt wasting
  • Present in adolescent/young women as premature puberty, acne, hirsutism, irregular menses/amenorrhoea (similar to PCOS). Females have normal genitalia.
  • High serum 17-OHP + testosterone
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What happens in 11-hydroxylase deficiency?

A

11-hydroxylase deficiency –> defective conversion from 11-deoxycorticosterone (weak mineralcorticoid activity) to corticosterone and 11-deoxycortisol (limited activity) to cortisol

Get overproduction of androgens

= females get ambiguous genitalia
= Hypernatraemia, hypokalaemia, hypertension due to increased mineralcorticoid activity from 11-deoxycorticosterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

How to diagnose 11-hydroxylase deficiency?

A

High serum 11-deoxycortisol
High androgens

If diagnosis is uncertain, can do ACTH stimulation test - would expect both to go up

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Rx 11-hydroxylase deficiency

A

Cortisol replacement

Antihypertensives

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Are adrenal masses generally benign?

A

Yes
Increases with age
Common incidental finding
Usually don’t produce hormones

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What do we worry about when we see bilateral adrenal masses?

A

Metastasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

DDx adrenal masses

A

Adrenal adenomas - 75% non-functioning
Pheochromocytoma
Adrenal corticoid carcinoma
Metastasis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What characteristics in an adrenal mass point towards it being benign?

A

Small, usually ≤3cm, ≥6cm needs investigation

Homogenous texture, ≤10 housefield units tend to be benign. >10HU more likely to be ACC, pheo, mets

Round/oval, smooth margins

Usually solitary, unilateral (bilateral suggests mets)

Minimally vascular on CT (ACC, pheo, mets usually vascular)

High washout rate (compaerd to ACC, pheo, mets)

Isointense in relation to liver on MRI (others are hyperintense)

No necrosis, haemorrhage or calcification

Stable or very slow growth

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What investigations might you do for an adrenal mass?

A

Non-contrast CT adrenals

1mg dexamethasone suppression test - give 1mg dex the night before then check cortisol at 8am. If high cortisol, it means the adrenal is producing it without ACTH

Aldosterone renin ratio - high aldosterone and suppressed renin tell us the adrenals are producing aldosterone on their own

Fasting plasma metanephrines - to exlude pheo

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Should we biopsy adrenal masses?

A

No

Due to risk of spread if adrenal corticoid carcinoma

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

What tests to do in bilateral adrenal hyperplasia?

A

Serum 17-hydroxyprogesterone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

When to do an adrenalectomy when there is an adrenal mass?

A

Suspect malignancy or if there is cortisol excess

Unilateral >6cm size
If 4-6cm, may choose to monitor growth every 6-12 months and consider surgery if growth is fast.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

High aldosterone leads to…

A

Holds onto Na+, water, loses K+, hydrogen ions

= hypervolemia, hypertension, hypokalaemia, metabolic alkalosis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Causes of primary hyperaldosteronism

A

Bilateral adrenal hyperplasia (most common)
Adrenal adenoma (Conn syndrome)
Adrenal corticoid carcinoma (rare)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

What drugs can affect aldosterone renin ratio?

A

Any antihypertensives (works by volume depletion or vasodilation) –> increase renin

Low potassium –> decreases aldosterone
High potassium –> increases aldosterone

Aldosterone antagonists e.g. spironolactone, amiloride, epleronone

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

How does AKI affect aldosterone renin ratio?

A

AKI –> fluid and salt retention –> decrease renin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What’s the seated saline suppression test?

A

Give sodium loading –> expect aldosterone to go down –> if it doesn’t, you know its autonomous production = primary aldosteronism

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

What’s adrenal venous sampling and when do you do it?

A

Insert catheter through groin –> to left and right adrenal vein –> measure cortisol and aldosterone

Tells us which adrenal gland is the problematic one or whether its both

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Right adrenal vein drains into.... | Left adrenal vein drains into....
Right adrenal vein drains into IVC | Left adrenal vein drains into left renal vein
26
Rx primary aldosteronism
Aldosterone antagonist - spironolactone, epleronone, amiloride Adenomas are usually surgically resected
27
Prognosis of adrenal corticoid carcinoma
Poor | 5 year survival <15%
28
How does adrenal corticoid carcinoma present?
1) Excess hormones Usually 2+ hormones Cortisol > androgens 2) Flank mass/pain 3) Incidental finding on imaging - Very big - >6cm - Heterogenous
29
Rx adrenal corticoid carcinoma
1) Surgical resection 2) Mitotane - Causes adrenal necrosis - Improves survival and recurrence 3) Chemotherapy - Slightly better progression of disease but no effect on survival
30
Causes of secondary hyperaldosteronism
Renal artery stenosis Fibromuscular hyperplasia in young people Atherosclerosis in old people Renal artery stenosis --> activation of the juxtaglomerular apparatus --> release renin --> converts angiotensinogen to ACEI --> ACEII --> activate adrenal gland to release aldosterone
31
What would you expect the renin and aldosterone to be in secondary hyperaldosteronism?
High renin and aldosterone
32
What would you expect the renin and aldosterone to be in primary hyperaldosteronism?
Low renin and high aldosterone
33
When does cortisol level peak?
Morning
34
Causes of high cortisol
Stress e.g. infection, trauma Starvation/anorexic nervosa Pregnancy Alzheimer's Pseudocushing's syndrome Glucocorticoid resistance Prenatal glucocorticoid excess Pituitary tumour (Cushing's disease) Ectopic ACTH source e.g. small cell carcinoma Adrenal tumour Exogenous glucocorticoid
35
What's pseudocushing's syndrome?
High cortisol but no tumour Related to depression, ETOH excess or can be idiopathic Lack of progression of Cushing's features
36
Clinical features of Cushing's
Proximal muscle weakness Moon facies, central adiposity, buffalo hump Abdominal striae (>1cm pathognomonic for pregnancy or Cushing) Hypertension + hypokalaemic + metabolic alkalosis (at very high levels, cortisol cross reacts with mineralcorticoid receptors) Osteoporosis Immunosuppression (late) especially prone to cellulitis
37
Diagnostic approach to suspected Cushing's disease
1) 24h urine cortisol or midnight salivary cortisol level or low dose dexamethasone test 2) Plasma ACTH If low ACTH --> CT adrenals If high ACTH --> do high dose dexamethasone test (will tell us whether ACTH is coming from hypothalamus or ectopic) --> CRH stimulation test - give CRH then measure ACTH and cortisol. Pituitary adenomas will respond by releasing more ACTH and cortisol. Ectopic source of ACTH and adrenal adenomas will not respond. --> IPSS if both tests are inconclusive.
38
What do you expect the adrenal glands to look like in excess exogenous glucocorticoids?
Bilateral adrenal atrophy (due to shut down of ACTH)
39
What do you expect the adrenal glands to look like in ACTH secreting pituitary adenoma (Cushing's)?
Bilateral adrenal hyperplasia
40
What do you expect the adrenal glands to look like in ectopic ACTH secretion?
Bilateral adrenal hyperplasia
41
What do you expect the adrenal glands to look like in primary adrenal adenoma?
One adrenal has adenoma/carcinoma The other is atrophied (due to it being shut down by low ACTH) OR Bilateral adrenal hyperplasia
42
Rx persistent Cushing's
Irreversible options Surgery Radiotherapy Mitotane ``` Reversible options Pasireotide Cabergoline Ketoconazole Metyrapone IV etomidate (emergency) Mifepristone ```
43
What happens in 17-hydroxylase deficiency?
Decreased androgens and cortisol - Primary amenorrhoea and lack of pubic hair in females - Pseudohermaphroditism in males Get increased weak mineralcorticoid (11-DOC) --> hypertension, mild hypokalaemia. Low aldosterone.
44
Rx for 21-hydroxylase deficiency
Mineralcorticoids | Glucocorticoids
45
Rx for 17-hydroxylase deficiency
Glucocorticoids | Sex steroids
46
Causes of adrenal insufficiency
Acute - Abrupt withdrawal of steroids - Adrenal haemorrhage - Pituitary problem (secondary adrenal insufficiency) - pituitary tumour, tumour of the hypothalamic-pituitary region, pituitary radiation, lymphocytic hypophysitis - Hypothalamus problem (tertiary adrenal insufficiency) Chronic (Addison's) - Autoimmune destruction (associated with other autoimmune disease such as Hashimoto's thyroiditis) - TB, HIV - Metastatic carcinoma e.g. from lung - Congenital - congenital adrenal hypoplasia, ACTH resistance
47
Clinical features of adrenal insufficiency
Low cortisol --> hypotension, weakness, diarrhoea, vomiting, abdo pain, hypoglycaemia Postural hypotension is a very specific sign - drop BP, raised HR on standing Low mineralcorticoids --> lose water, lose Na+, retain K+, keep hydrogen ions --> hypovolaemia, hyponatraemia, hyperkalaemia, metabolic acidosis Features of high ACTH --> stimulates melanocytes --> hyperpigmentation (takes time)
48
What clinical feature helps distinguish primary from secondary adrenal insufficiency?
Hyperpigmentation from too much ACTH (primary insufficiency)
49
Rx adrenal insufficiency
1) hydrocortisone or cortisone or pred - Don't give dex as it doesn't have mineralcorticoid effect. 2) Fludrocortisone - Monitor electrolytes, renin
50
Symptoms of adrenal crisis
Cardinal symptom is hypotension | Anorexia, nausea, vomiting, weakness, fatigue, abdo pain, diarrhoea, confusion, coma, fever
51
Who gets adrenal crisis?
Undiagnosed people with adrenal insufficiency having an infection People with adrenal insufficiency who fails to stress dose Bilateral adrenal infarction/haemorrhage
52
How much do you stress dose in someone with adrenal insufficiency who is unwell?
Triple dose for 3 days - Hydrocortisone 100mg stat then 50mg Q6H until stable and tolerating oral intake Particularly if there is infection, fever If they can't take tablet, then IM/SC hydrocortisone 100mg emergency injection kit (tie people over for 12 hours before they can present to ED) or prednisolone/hydrocortisone suppository
53
Labs in adrenal crisis
Low sodium High potassium Low glucose High calcium
54
Autoimmune Addison's disease is often associated with ...
T1DM
55
Adrenal medulla - its main function is ...
Produces catecholamines (adrenaline and noradrenaline)
56
Clinical features of pheochromocytoma
Due to increased serum catecholamines ``` Episodic HTN Headache Palpitations Tachycardia Sweating ```
57
How to diagnose pheochromocytoma?
Serum metanephrine (usually pretty good) or 24h urine metanephrine If >2 fold elevation above ULN, localise with adrenal/abdominal MRI or CT +/- I-MIBG (nuclear med scan with iodine) Consider genetic testing
58
Rx pheochromocytoma
Pre-op preparation Alpha blockade - phenoxybenzamine, prazosin Beta blockade - propanolol, atenolol, labetalol If possible, beta blockade must not be started in patients until alpha blockade has been established. - Can cause dramatically elevated BP, due to unopposed alpha-adrenoreceptor stimulation Then... Surgery
59
What syndrome is pheochromocytoma associated with?
MEN2A and 2B Neurofibromatosis type 1 Hippel-Lindau disease
60
Why do we check cortisol in the morning?
Diurnal | Peaks at 8am
61
Rx adrenal crisis
IV hydrocortisone 100mg then 50mg Q6H until stable + intravascular volume expansion Hydrocortisone preferred as the 1st line therapy because at higher dose (>60-80mg), it also has mineralcorticoid effect, hence bypass the need to worry about starting fludrocortisone initially
62
Rx CAH i.e. 21-hydroxylase deficiency
Glucocorticoid Mineralcorticoid New: gene therapy (coming)
63
Adrenal incidentaloma DDx
Cortisol or aldosterone secreting adenoma (14%) - most common Phaeochromocytoma (7%) Adrenalcortical carcinoma or metastatic carcinoma (4%)
64
Do all primary hyperaldosteronism cause hypokalaemia?
NO | 30% have normal K
65
What is the most common cause of primary aldosteronism related hypertension?
Bilateral idiopathic hyperplasia 60% Aldosterone producing adenoma 30%

Endocrinology (9 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions