Manipulating Renal Physiology Flashcards
Where can you find the counter current multiplier?
Loop of henle
Which out of the afferent and efferent arterioles has the narrowest lumen ?
Efferent
What is the job of the podocytes?
To filter out large molecules and keep them in the blood
What 6 molecules are sodium co-transport linked too?
Glucose, amino acids, hydrogen ions, phosphate, chloride flux,water (follows sodium passively)
What role does the loop of henle play?
it concentrates the urine
How does the macula densa control filtration rate?
If filtration rate too fast it constricts afferent arteriole and if too slow it activates RAS system
What does renin do?
Cleaves angiotensinogen to form angiotensin I
Where can ACE be found that converts angiotensin I to angiotensin II?
The lungs
What effect does angiotensin II have?
Constricts the efferent aa, Enhances Na+ and water absorbtion by PCT and stimulates aldosterone system
What effects will ACE inhibitors have on filtration rate?
They will increase glomerular filtration
Where is the composition of urine finely regulated?
Distal tubule and collecting duct.
What part of the kidney does ADH work on ?
The collecting duct
What kind of diuretic is furosemide?
It is a loop diuretic
Where do thiazide diuretics have an effect?
On the early distal tubule
Where do thiazide diuretics bind?
Bind to the Cl- site of the na/cl transporter.
Where do potassium diuretics work in the nephron?
Collecting duct
What action do they have?
They inhibit the action of aldosterone
Grade the diuretics in order of their diuretic effect
Loop diuretics cause loss of 25% of filtered load, Thiazide diuretics caise 10% loss of filtered load and potassium sparing diuretics diuretics are the weakest diuretics
How do loop diuretics work?
They competitively bind to the cl- site of the Na/cl/k symporter… preventing uptake of the ions and therefore the subsequent following of water
How can diuretics effect pre load?
They can reduce preload to the point that is negatively effects cardiac output
What negative side effect can furosemide have on blood ion levels?
It can cause hypokaleaemia by losing too much sodium
What other type of diuretic can also cause hypokaleaemia?
Potassium sparing diuretics
How do diuretics interact with vasodilators?
They are synergistic
How do NSAIDS interact with diuretics?
They exacerbate water and salt retention reducing diuretic efficacy
