Flashcards in Renal Deck (216)
What is another name for an epithelial foot process?
What is pyelonephritis?
Pus in the kidney
What is reflux nephropathy and why does it occur and what can it lead to?
Occurs in childhood when the kidneys are growing
Have an incompetent vesicoureteric junction
On voiding urine passes back up ureter then back into bladder, there is risk of stagnation and infection
On voiding infected urine passes back up to the kidneys - pyelonephritis - injury and scarring
Can lead to CKD
What is the clinical presentation of reflux nephropathy and what is the treatment?
Child with fever of unknown origin
Fails to meet developmental mile stones - bedwetting at 5-7 years
Family history of reflux nephropathy
Treatment is prophylactic Abx
If haematuria was found in a patient over 45 what would you suspect and who would you refer them to?
Suspect a lesion somewhere in the renal tract
Refer to a urologist
If haematuria was found in a patient under 45 what would you suspect and who would you refer them to?
refer to the renal physician
What is glomerulonephritis?
Inflammation in the glomerulus
What 4 things make up nephrotic syndrome?
What happens in nephrotic syndrome to the glomerulus?
Injury to the foot processes of the nephron
What 4 things can cause injury to the foot processes of the nephron and therefore nephrotic syndrome?
1) Minimal change disease (children)
2) Membranous nephropathy
3) Focal segmented glomerulosclerosis
4) Amyloid (caused by myeloma, malignancy of the bone marrow)
What is the most important way by which foot processes in health prevent the filtration of albumin from the blood?
Repel them by being negatively charged
What 4 important substances are freely filtered into the nephron?
3) Amino acids
What 3 things affect the filtration of a molecule across the glomerular basement membrane?
1) Molecular weight
2) Surface charge - glomerular basement membrane is negatively charged
3) Hydrostatic pressure in the afferent arteriole
What is a normal glomerular filtration rate?
What does accurate glomerular filtration rate measurement require the injection of and when is this carried out?
The injection of a radioactive tracer such as Technetium Tc99
Performed rarely except in the case of live kidney donors to determine accurate kidney function prior to donation
What is performed as an alternative to glomerular filtration rate but is not used often clinically? Is this more or less accurate?
Not as accurate
Requires a blood test and 24 hour urine collection
What is the routinely used measurement of kidney function?
Simple blood test
Normal range is 64-104 umol/L
What 4 things are required to calculate eGFR?
1) Serum creatinine
What does eGFR correlate with?
Percentage kidney function
At what eGFR do patients need to commence dialysis?
At what level is plasma osmolality maintained at to maintain normal cellular function?
What is a normal urine osmolality?
What mechanism is responsible for the kidneys ability to produce concentrated urine during periods of decreased fluid intake?
Counter current mechanism
Establishes a high conc gradient in the medulla and enables water resorption in the proximal tubule and the collecting duct
What are the 3 methods of insensible loss of fluid?
How does antidiuretic hormone increase fluid retention?
Inserts channels into the medullary collecting duct to allow reabsorption of water
What 2 things can uraemia (accumulation of waste products) lead to?
Where is the Na+/K+ATPase in the nephron?
In all sections of the nephron
Located on the apical (blood) side
Pumps 3Na+ out for 2 K+ in
What percentage of glomerular filtrate is recovered at the proximal convoluted tubule?
70% (water and electrolytes)
At what point in the nephron is bicarbonate regenerated?
Proximal convoluted tubule