Aldosterone vs ADH

From FK Wiki
Jump to: navigation, search

Block A4 - Genito-Urinary System


Water follows sodium
The ascending loop of Henle is not permeable to water
Principal cells reabsorb Na+ and secrete K+. Intercalated cells reabsorb K+ and bicarbonate icons and secrete H+.
Renin-angiotensin-aldosterone system.

The main difference is that ADH preserves water in a more direct manner while aldosterone preserves water in a more indirect way by first retaining sodium. Remember, water always follows sodium.

ADH (vasopressin) Aldosterone
Type of hormone: peptide hormone steroid hormone, part of the renin-angiotensin system
Produced by: hypothalamus the outer section (zona glomerulosa) of the adrenal cortex in the adrenal gland
Stored in: posterior pituitary and released into blood stream or brain directly.
Effects on cardiovascular system: moderate vasoconstriction and increased blood pressure. conservation of sodium, secretion of potassium, increased water retention, and increased blood pressure due to increased blood volume.
Effects on kidney's CD and DCT: increased water permeability of the kidney's collecting duct (CD) and distal convoluted tubule (DCT) by inducing translocation of aquaporin-CD water channels in the kidney nephron collecting duct plasma membrane. Thus, increased water reabsorption in distal convoluted tubules and collecting ducts of the nephron, producing concentrated urine. water and sodium reabsorption in distal convoluted tubules and collecting ducts of the nephron, producing concentrated urine.
Secreted when: body is dehydrated blood pressure is low
Secreted in response to: reductions in plasma volume, in response to increases in the plasma osmolality, and in response to cholecystokinin (CCK) secreted by the small intestine: increased plasma angiotensin II, ACTH, or potassium levels. Also, lower blood pressure detected by the stretch receptors located in the atria of the heart.
Inhibited by: Diuretics such as alcohol (CH3-CH2-OH). So, drinking alcohol will inhibit reabsorption of water and thus produce more urine. ACE inhibitors, potassium depletion, dopamine, and atrial natriuretic hormone (ANH) which has exactly the opposite effect of aldosterone.

Links[edit]