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Flashcards in Adrenals Deck (22):
1

What is the cortex to medulla ratio?

90%:`10%

2

What are the parts of the cortex? What do they do?

- zona glomerulosa (secrete mineralocorticoids - aldosterone)
- zona fasciculus (glucocorticoids - cortisol)
- zona reticularis (androgens) (and glucocorticoids)

3

What cells are contained in the medulla? What do they do?

Chromaffin cells - release catecholamines (adrenaline and noradrenaline)

4

What are the differences in shape between the right and left adrenal glands?

Right - pyramidal
Left - crescentic

5

How does blood supply get to the adrenal glands?

- subscapular plexus -> vessels -> fenestrated sinusoids
- most cells 1/2 away from vascular endothelial cell

6

What initiates steroid production in the cortex?

Cholesterol uptake and conversion

7

What does hyperaldosteronism cause?

Low potassium, high blood pressure and alkalosis, suppressed renin activity
(high aldosterone)
(Conn's syndrome)

8

How do you diagnosis hyperaldosteronism?

- aldosterone:renin ratio
- CT adrenal
- adrenal venous sampling

9

What is the mineralocorticoid receptor?

- aldosterone binds to them
- expressed in the nucleus
- cortisol also binds but cortisone inactivates unless overwhelming conditions

10

What are the functions of aldosterone?

- stimulates Na/K ATPase and increases expression
- inserts additional ENacs
- stimulates H+ ATPase channel
(THEREFORE when excess loss of H+ = metabolic alkalosis and K+ loss balancing intake of Na+)

11

What is Liddle's syndrome?

Increased expression of ENac = hypertension, hypokalemia, metabolic alkalosis

12

What are the function of glucocorticoids?

Deal with stress:
starvation -> breakdown fuels
infection -> immunosuppression
Hypotension -> increase BP

13

What are the causes of Cushing's?

- iatrogenic
- corticotroph adenoma of the pituitary!!!
- bilateral adrenal hyperplasia
- cortisol secreting adrenal adenoma

14

How is Cushing's diagnosed?

- dexamethasone suppression test overnight
- 24 hour urine free cortisol
- MRI pituitary
- CT adrenals

15

How do you treat Cushing's?

PITUITARY: transphenoidal surgery, external beam radiotherapy, stereotactic radiosurgery

ADRENAL: adrenalectomy, etomidate

16

Symptoms of Addison's disease?

fatigue, weakness, myalgia, anorexia, weight loss, hyperpigmentation

17

Causes of primary adrenal failure?

Autoimmune
TB

18

What is Addison's disease?

when something stressful happens and cannot respond to it = low bp, sodium, potassium, glucose

19

How do you diagnose Addison's?

Low 9am cortisol
high ACTH

20

How do you treat Addison's?

- replace steroid with hydrocortisone and fludrocortisone (mineralocorticoid)
- IV fluid resuscitation
- IM hydrocortisone

21

What is congenital adrenal hyperplasia?

Defect in conversion to aldosterone and cortisol and excess ACTH secreted as no negative feedback
- stimulate cholesterol uptake in adrenal gland which is converted to cortisol then into testosterone

22

What kind of stress do stress hormones respond to?

Starvation
Infection
Severe volume loss