Na/K Balance Related Pathologies

Question 1

What does the Cortex produce?

Answer 1

glucocorticoid hormones (e.g. Cortisol)
Mineralocorticoid hormones (e.g. Aldosterone)
Sex hormones (androgens & estrogens)

Question 2

What is the occurence of Addison’s disease?

Answer 2

Primary Adrenal Insufficiency aka Addison’s disease (very rare ) as opposed to secondary adrenal insufficiency

Question 3

What is the consequence of cortex damage?

Answer 3

Damage to cortex ⇒↓↓ hormone production ⇒ numerous symptoms

Question 4

What does a deficiency in aldosterone cause?

Answer 4

Deficiency in aldosterone ⇒
Body secreting large amounts Na ⇒ low serum Na levels
Body retaining K ⇒ hyperkalaemia

Question 5

How would we treat aldosterone deficiency?

Answer 5

Treatment usually involves corticosteroid (steroid) replacement therapy for life

Question 6

What are the effects of secondary adrenal insufficiency?

Answer 6

Pituitary ACTH ↓
Cortisol ↓
Adrenal glands shrink

Question 7

What is Conn’s Syndrome?

Answer 7

Primary Aldosteronism aka Conn’s Syndrome

Question 8

What causes Conn’s syndrome?

Answer 8

Due to aldosterone-producing adenoma of ZG of adrenal gland

usually <3cm, unilateral & renin-unresponsive

Question 9

What is hyperaldosteronism?

Answer 9

Excess release of aldosterone

Aldosterone even released in absence of stimulation by Angiotensin II

Question 10

What causes hyperaldosteronism?

Answer 10

due to variety chronic disease
Most common (50-60%) due to Conn’s syndrome, remaining 40-50% due to bilateral adrenal hyperplasia

Question 11

What is the consequence of hyperaldosteronism?

Answer 11

↑↑↑ Plasma Aldosterone ⇒ kidneys to stimulate Na+ reabsorption & K+ excretion ⇒ develop hypertension* ⇒ ↑fluid volume ⇒ hypokalaemia (↓[K+]), hypernatremia and alkalosis
*↑bp & Na delivery to macula densa ⇒ ↓↓release of renin ⇒ renin-independent cause of hypertension (very difficult to control)

Question 12

What is the treatment fro hyperaldosteronism?

Answer 12

surgical removal of tumour-containing adrenal gland

hypertension & hypokalaemia controlled with K+-sparing agents e.g spironolactone