Reading...
Play button
Play button
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;
59 Cards in this Set
- Front
- Back
|
List the 6 functions of the kidneys:
|
1. Urine formation
2. Fluid/electrolyte balance 3. Acid-base balance 4. Waste excretion 5. Hormone function 6. Protein conservation |
|
|
What 3 processes occur to allow urine formation?
|
Filtration
Reabsorption Secretion |
|
|
What 3 waste products are removed by the kidneys?
|
1. Urea
2. Creatinine 3. Uric acid |
|
|
What 3 hormones are regulated by the kidneys?
|
1. Vitamin D - active form is produced
2. Renin - produced 3. Erythropoeitin |
|
|
How much blood supplies the kidneys?
what %body wt are the kidneys? |
-25% of cardiac output
-0.5% |
|
|
What transport occurs in the proximal convoluted tubule?
|
1. Active transport of Glucose, amino acids, Na, K.
2. Water follows 3. Passive reabsorption of negative ions |
|
|
What transport occurs in the loop of Henle?
|
Active transport of Cl-
|
|
|
What transport occurs in the distal convoluted tubule?
|
Active transport of Na, K, H.
|
|
|
What controls Na/K/H2O transport in the distal tubule?
|
Aldosterone
|
|
|
What is the tonicity of filtrate as it leaves the distal tubule?
|
Isotonic to hypotonic
|
|
|
What happens to the filtrate tonicity when it enters the collecting duct?
|
Becomes hypertonic - H2O gets reabsorbed so the ion concentration increases.
|
|
|
What allows the filtrate to become hypertonic in the collecting duct? What controls this?
|
-The reabsorption of Water from the filtrate.
-Controlled by ADH |
|
|
What is the function of ADH?
|
Increased permeability of collecting duct to H2O
|
|
|
How does the kidney buffer body pH?
|
-Excretion of organic acids and H+
-Ammonia -Phosphate |
|
|
What exactly is Urea?
|
Major nitrogen waste product from protein breakdown
|
|
|
How is Urea formed?
|
-Liver deaminates a. acids
-Produces ammonia -Intest bacteria degrade NH3 |
|
|
What is the name of the chemistry test for Urea?
|
BUN - blood urea nitrogen
|
|
|
How is Urea excreted?
|
1. Glomerulus filters it at a constant rate
2. 40% is reabsorbed passively 3. Final excretion amt depends on protein diet and metabolism. |
|
|
How do these physiological factors affect the BUN?
-Liver disease -High protein diet -Starvation -Dehydration -Kidney disease |
Liver dis: decreased BUN
Hi-protein diet: increased BUN Starvation: increased plasma urea Dehydration: increased BUN Kidney disease: increased BUN |
|
|
what is azotemia?
|
Increased urea waste products in the serum
|
|
|
What are 6 pre-renal causes of azotemia?
|
-Dehydration
-GI hemorrhage -CHF -Increased protein -Starvation -Cortisol/mannitol treatment |
|
|
What are 4 renal causes of azotemia?
|
1. Vascular - arteriosclerosis
2. Glomerular disease 3. Acute tubular necrosis 4. Pyelonephritis |
|
|
What causes post-renal azotemia?
|
Obstruction of urine flow - through ureters, bladder or urethra.
|
|
|
List 4 causes of a decreased BUN:
|
1. Liver disease
2. Malnourishment 3. Decreased protein diet 4. Over-hydration |
|
|
What is Creatinine formed from?
|
Muscle creatine and phosphocreatine
|
|
|
How closely does Urine creatinine measurement approximate the GFR?
|
Close, but it overestimates it b/c about 10% is excreted.
|
|
|
Does creatinine fluctuate much in normal individuals?
|
No; it is relatively constant b/c it's a muscle byproduct.
|
|
|
How much of the body creatinine is filtered by the glomerulus?
|
About 90%
|
|
|
How do the urine Creat and the BUN change with decreasing Renal function?
|
They both increase
|
|
|
what is the normal Creat ref range?
|
0.6-1.2 mg/dl
|
|
|
what is the normal BUN ref range?
|
7-18 mg/dl
|
|
|
how high do the creat and bun get in renal failure?
|
Creat = about 10 mg/dl
BUN = about 35-110 mg/dl |
|
|
how high do the creat and bun get in uremic syndrome?
|
Creat = >8 mg/dl
BUN = >80 mg/dl |
|
|
List 3 tests for glomerular function:
|
1. Creatinine clearance
2. Inulin clearance 3. Urea clearance |
|
|
How is the Creatinine clearance calculated?
|
see flashcard.
|
|
|
How is inulin clearance different from creatinine?
|
Inulin is given exogenously.
|
|
|
Which clearance test more accurately parralels the GFR?
|
Urea clearance
|
|
|
List 4 tests for evaluating Tubular Function:
|
1. Phenolsulfonphthalein (PSP)
2. Specific gravity 3. Osmolality 4. Concentration tests |
|
|
What is the principle of the PSP test?
|
-Dye is given exogenously, the secretion is measured to determine how well the tubules function.
|
|
|
What is the definition of urine specific gravity?
|
The weight of dissolved solutes in the urine compared to water.
|
|
|
What is a normal specific gravity?
|
Above 1.000 (sp gr of H2O) up to about 1.030
|
|
|
What is a dilute Sp gr?
|
<1.010
|
|
|
What 3 methods are used for measuring specific gravity?
|
1. Densitometry
2. T-S meter (refractometer) 3. Dipstick |
|
|
How is osmolality different from specific gravity?
|
It takes into account the number of molecules, not just the weight.
|
|
|
What is the normal serum osmolality?
|
285-300 mOsm/kg
|
|
|
What is the normal urine osmolality?
|
App. 600 mOsm/kg
|
|
|
What is the normal Urine:Serum osmolality ratio?
|
1-3
|
|
|
After 12 hrs of fluid restriction what is the Urine:serum osmol. ratio?
|
Increased; 3-4.7
|
|
|
How does Urine:serum osmolality ratio change with:
-Renal tubular deficiency? -Diabetes insipidus? |
Ren. tubular. def: decreased
Diabetes insipidus: 0.2-.7 |
|
|
What is the definition of urine specific gravity?
|
The weight of dissolved solutes in the urine compared to water.
|
|
|
What is a normal specific gravity?
|
Above 1.000 (sp gr of H2O) up to about 1.030
|
|
|
What is a dilute Sp gr?
|
<1.010
|
|
|
What 3 methods are used for measuring specific gravity?
|
1. Densitometry
2. T-S meter (refractometer) 3. Dipstick |
|
|
How is osmolality different from specific gravity?
|
It takes into account the number of molecules, not just the weight.
|
|
|
What is the normal serum osmolality?
|
285-300 mOsm/kg
|
|
|
What is the normal urine osmolality?
|
App. 600 mOsm/kg
|
|
|
What is the normal Urine:Serum osmolality ratio?
|
1-3
|
|
|
After 12 hrs of fluid restriction what is the Urine:serum osmol. ratio?
|
Increased; 3-4.7
|
|
|
How does Urine:serum osmolality ratio change with:
-Renal tubular deficiency? -Diabetes insipidus? |
Ren. tubular. def: decreased
Diabetes insipidus: 0.2-.7 |
