Please enable JavaScript.

Coggle requires JavaScript to display documents.

Diabetes insipidus (Diagnosis (Investigations (Plasma and urine osmolality…

- - - - If urine output low and osmolality high, then both ADH secretion and the renal response are present (cause most likely extrarenal water loss)
      - If both urine output and urine osmolality are high - osmotic diuresis is suspected
      - If urine output is high and urine osmolality isless than plasma osmo, then the cause is due to ADH secretion or abnormal response to ADH
- - - - Incr plasma osmolality (>1% from set point 285)
      - Hypovolaemia (overides osmotic regulation, allowing kidney to conserve water)
      - Angiotensin II
      - Pain, stress, emotion, exercise
    - - Activates V2 receptors on principal cells in the collecting duct
      - Via 2nd messenger cAMP, inserts aquaporin water channels into the luminal membrane
      - Water is conserved in excess of solutes and a small volume of hyperosmotic (concn) urine is excreted
      - Leads to decreased plasma osmolality, creating a negative feedback loop and cessation of ADH release