Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
21 Cards in this Set
- Front
- Back
|
Produced in supraoptic and paraventricular nuclei of hypothalamus. Stored in posterior lobe of pituitary |
Arginine Vasopressin, (AVP) (ADH) |
|
|
Released in response to plasma osmolality - Promotes solute free water resorption at the level of the distal renal tubule and collecting ducts via V2 receptors and aquaporin-2 channels |
Actions of vasopressin |
|
|
Small changes in pOsm result in larger changes in __ |
Arginine Vasopressin (AVP) |
|
|
Urine osmolality increases until maximal and then __ in response to vasopressin |
plateus |
|
|
__ rapidly decreases in response to AVP |
Urine volume |
|
|
vasopressin regulates urea absorption in: |
inner renal medullary collecting duct |
|
|
vasopressin binds to endothelial V2 receptors, causing release of: |
Factor VIII and vWF |
|
|
vasopressin increases: |
BP, platelet aggregation, potentiation of CRH and behavioral responses (as a neurotransmitter) |
|
|
vasopressin cannot |
Reduce urine output completely / Decrease water loss from other areas (faeces, evaporation etc) |
|
|
Thirst mechanism: __ are sensitive to changes in osmolality. Higher threshold than vasopressin |
Hypothalamic receptors |
|
|
polyuria = urine output __ ml/kg/day |
> 50 |
|
|
polydipsia = water intake __ ml/kg/day (dogs)Water intake __ ml/kg/day (cats) |
> 100, > 50 |
|
|
Excess drinking causing excess urination(what goes in must come out) |
Primary polydipsia |
|
|
Excess urination with compensatory polydipsia(what is lost must be replaced) |
Primary polyuria |
|
|
Vasopressin deficiency (Central diabetes insipidus (DI)) Primary nephrogenic DI Acquired nephrogenic DI (‘Secondary’) Osmotic diuresis |
ddx primary polyuria |
|
|
damaging __ may cause temporary DI |
pituitary stalk |
|
|
Post-obstructive diuresis (Urea etc.) Glucosuria (primary renal glycosuria / Fanconi syndromediabetes mellitus) Drugs (mannitol) |
causes of osmotic diuresis |
|
|
Genetic mutationsV2 receptor Aquaporin-2 InheritedSpecific breeds e.g. HuskiesMay be multiples affected |
Primary nephrogenic DI |
|
|
for Dx PUPD, distinguish from |
Incontinence, pollakiuria, periuria |
|
|
Differentials for hyposthenuria |
Primary polydipsiaCentral diabetes insipidusPrimary nephrogenic DIHepatic diseaseHyperadrenocorticismHypoadrenocorticismHypercalcaemiaInfections |
|
|
eliminate: __ in investigation of PUPD |
hepatic ds, hyperarenocorticism, pyelonephritis |
