Aldosterone
| Adrenal | Total cortisol rises; free cortisol is unchanged; aldosterone rises (salt and water retention) |
What our notes say
- | Adrenal | Total cortisol rises; free cortisol is unchanged; aldosterone rises (salt and water retention) | (Physiological changes in pregnancy)
- His plasma renin activity is 0.1 ng/mL/hr and his serum aldosterone 65 ng/mL. (Chemical pathology and Endocrine pathology — Past Paper Questions & Answers)
- Aldosterone (B) is the main mineralocorticoid; DHEA (C) and androstenedione (D) are adrenal androgens, not glucocorticoids. (bchem EOY 2011 — Past Paper Questions & Answers)
- The fall in intravascular volume activates the renin-angiotensin-aldosterone system and ADH, so the kidney retains salt and water, and some primary sodium retention at the distal nephron (overfill) adds to the swelling. (Paediatrics and Child Health end of semester examination (MBPE): 10 January 2023)
- Aldosterone (mineralocorticoid receptor) antagonists (spironolactone, eplerenone) (Clinical Pharmacology I (MBPL 4400) main exam: 25 January 2023)
- Injured kidneys release renin, which activates angiotensin II and aldosterone, causing vasoconstriction and more sodium retention. (Paediatrics end of fourth year main exam: 1 July 2019, Paper One, 99 of 100 MCQs)
Study material on Aldosterone
- Endocrine & Renal Pathology
- LECTURE 6: Pancreatic and Adrenal Hormones
- Chemical Pathology Practice Examination
- Endocrine and Metabolic Pathology MCQs
- Endocrine and Metabolic Pathology MCQs: Practice Questions
- Endocrine & Renal Pathology — Must Know Notes
- ENDOCRINE PATHOLOGY
- Medical Physiology Paper II MCQs
- Endocrine and Metabolic Pathology MCQs for Medical Students
- Liver Function Tests (LFTs)
- Endocrine & Renal Pathology
- Endocrine & Renal Pathology
- END YEAR PP1 & PP2 2025 Physiology: MCQs for Medical School Exams
Practice questions on Aldosterone
Aldosterone primarily acts on which part of the nephron to increase sodium reabsorption and potassium secretion?
- Proximal convoluted tubule
- Loop of Henle (thick ascending limb)
- Distal convoluted tubule and collecting duct
- Glomerulus
Answer: C. Aldosterone, a mineralocorticoid, primarily acts on the principal cells in the late distal convoluted tubule and cortical collecting duct. It stimulates the insertion of more ENaC channels (for Na+ reabsorption) and ROMK channels (for K+ secretion) into the apical membrane, and Na+/K+-ATPase pumps into the basolateral membrane, leading to increased Na+ reabsorption and K+ secretion. The other segments (A, B, D) are n
Secretion of aldosterone would be affected if which layer of the adrenal cortex is damaged? ---
- Zona reticularis
- Zona fasciculata
- Zona glomerulosa
- Zona fasciculata and reticularis
- Fasciculata makes cortisol; reticularis makes sex steroids.
Answer: C.
Stimulation of the renin-angiotensin-aldosterone system (RAAS) by the kidney primarily occurs in response to ---
- Decreased potassium levels in extracellular fluid
- Decreased atrial natriuretic peptide (ANP) secretion
- Decreased sodium delivery to the distal tubule
- Decreased antidiuretic hormone (ADH) secretion
Answer: C.
What is the function of aldosterone? ---
- Increase sodium reabsorption in the kidneys
- Decrease sodium reabsorption
- Increase potassium reabsorption
- Decrease potassium excretion
Answer: A.