Renal Physiology Lab Flashcards
The chief regulators of the internal environment of the body
The Kidneys
How do the kidneys achieve homeostasis ?
They regulate the pH and concentration of ions and water in the various body fluids. They also provide for the elimination of the waste products of metabolism
The two main structures of the kidneys
The glomerulus and the renal tubule
How many nephrons are in the kidneys?
2 million
The rate at which blood is first filtered through the glomerulus?
120 ml/min; after first filtering through the glomerulus the filtrate then passes into the renal tubule
The tubular filtrate is similar to blood plasma in composition except that
Large molecules over 70,000 MW are excluded (e.g., plasma proteins)
Metabolism rate of toxic by-products
1 ml formed per minute
Toxic by-products of metabolism and substances in excess are…
Retained in the filtrate or are secreted into the filtrate and finally excreted in the urine. So the final composition of the urine is quite different from that of the glomerular filtrate.
Phenylpyruvic acid appears in the urine of this disease
Phenylketonuria (PKU)
This disease results in mental retardation
Phenylketonuria (PKU)
Disease characterized by a deficient production of insulin by the pancreas
Diabetes Mellitus
Caused by diabetes mellitus which results in the appearance of glucose in the urine
Glycosuria
The urinometer was calibrated to give a correct reading only if…
The urine is at 15 degrees Celsius
What do you need to do if your urine is at a different temperature?
You will need to correct the specific gravity by adding 0.001 for each 3 degrees celsius above, or by subtracting 0.001 for each 3 degrees celsius below the calibration temperature (15 degrees celsius)
The normal range of urine specific gravity is
1.0015 to 1.035; Readings above or below these limits may indicate a pathological condition
What is associated with a low reading of urine specific gravity?
Chronic Nephritis
What is associated with a high reading of urine specific gravity?
Acute Nephritis
A combined test of urinary pH, protein, glucose, ketones, and occult blood
The Labstix Test
Abnormally low pH along with high glucose and ketones indicates
Diabetes Mellitus
Condition where urine decomposes in the bladder with the production of ammonia
Cystitis
Urinary pH usually is
Slightly acid
Around pH 6
What can lower the pH of your urine?
A diet rich in proteins or citrus fruits
A disease in which the glomeruli are damaged and plasma proteins and erythrocytes leak into the nephrons
Nephritis
Used a reagent strip that we dipped in urine and watched the change in color
Labstix Test
When reading a Labstix strip its important to
In exactly 10 seconds read the glucose test portion. Exactly 5 seconds later read the ketone portion, and in exactly 15 more seconds read the occult blood portion (at the end of the strip). PH and protein portions may be read after this at your leisure, since time is not so critical with these two
If the urine glucose is found to be beyond the normal range, make a more accurate analysis for glucose by
Using the Clinitest tablets
If the urine pH is found to be beyond the normal range, make a more accurate analysis for pH by
Using the pHydrion paper
One of the kidney’s main functions is to regulate the osmolarity of the body fluids at around
300 milliosmoles per liter
When measuring chloride concentration
Place 10 drops of urine into test tube (use standard medicine dropper - 20 drops per ml)
Add one drop of 20% potassium chromate
Add 2.9% silver nitrate drop by drop til yellow becomes brown
Each drop of 2.9% silver nitrate is
1 g/liter of NaCl in the urine
3 experimental groups
800 ml water
800 ml water + 7 grams of NaCl
80 ml water + 7 grams of NaCl
3 graphs
ml of urine per minute
S.G.
Chloride Concentration (mg/ml)
What happens when we’re hydrated?
If we have too much water in our system, then we do not collect ADH and hence the walls of our collecting duct will not be permeable to water and therefore low concentrated filtrate comes in and large volume of low concentrated urine comes out
What happens when we’re dehydrated?
if one is dehydrated, neurons will increase firing rate and more ADH is secreted and collecting ducts become even more permeable to water and more water is retained
