Renal Physiology Lab

Question 1

The chief regulators of the internal environment of the body

Answer 1

The Kidneys

Question 2

How do the kidneys achieve homeostasis ?

Answer 2

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

Question 3

The two main structures of the kidneys

Answer 3

The glomerulus and the renal tubule

Question 4

How many nephrons are in the kidneys?

Answer 4

2 million

Question 5

The rate at which blood is first filtered through the glomerulus?

Answer 5

120 ml/min; after first filtering through the glomerulus the filtrate then passes into the renal tubule

Question 6

The tubular filtrate is similar to blood plasma in composition except that

Answer 6

Large molecules over 70,000 MW are excluded (e.g., plasma proteins)

Question 7

Metabolism rate of toxic by-products

Answer 7

1 ml formed per minute

Question 8

Toxic by-products of metabolism and substances in excess are…

Answer 8

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.

Question 9

Phenylpyruvic acid appears in the urine of this disease

Answer 9

Phenylketonuria (PKU)

Question 10

This disease results in mental retardation

Answer 10

Phenylketonuria (PKU)

Question 11

Disease characterized by a deficient production of insulin by the pancreas

Answer 11

Diabetes Mellitus

Question 12

Caused by diabetes mellitus which results in the appearance of glucose in the urine

Answer 12

Glycosuria

Question 13

The urinometer was calibrated to give a correct reading only if…

Answer 13

The urine is at 15 degrees Celsius

Question 14

What do you need to do if your urine is at a different temperature?

Answer 14

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)

Question 15

The normal range of urine specific gravity is

Answer 15

1.0015 to 1.035; Readings above or below these limits may indicate a pathological condition

Question 16

What is associated with a low reading of urine specific gravity?

Answer 16

Chronic Nephritis

Question 17

What is associated with a high reading of urine specific gravity?

Answer 17

Acute Nephritis

Question 18

A combined test of urinary pH, protein, glucose, ketones, and occult blood

Answer 18

The Labstix Test

Question 19

Abnormally low pH along with high glucose and ketones indicates

Answer 19

Diabetes Mellitus

Question 20

Condition where urine decomposes in the bladder with the production of ammonia

Answer 20

Cystitis

Question 21

Urinary pH usually is

Answer 21

Slightly acid

Around pH 6

Question 22

What can lower the pH of your urine?

Answer 22

A diet rich in proteins or citrus fruits

Question 23

A disease in which the glomeruli are damaged and plasma proteins and erythrocytes leak into the nephrons

Answer 23

Nephritis

Question 24

Used a reagent strip that we dipped in urine and watched the change in color

Answer 24

Labstix Test

Question 25

When reading a Labstix strip its important to

Answer 25

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

Question 26

If the urine glucose is found to be beyond the normal range, make a more accurate analysis for glucose by

Answer 26

Using the Clinitest tablets

Question 27

If the urine pH is found to be beyond the normal range, make a more accurate analysis for pH by

Answer 27

Using the pHydrion paper

Question 28

One of the kidney’s main functions is to regulate the osmolarity of the body fluids at around

Answer 28

300 milliosmoles per liter

Question 29

When measuring chloride concentration

Answer 29

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

Question 30

Each drop of 2.9% silver nitrate is

Answer 30

1 g/liter of NaCl in the urine

Question 31

3 experimental groups

Answer 31

800 ml water
800 ml water + 7 grams of NaCl
80 ml water + 7 grams of NaCl

Question 32

3 graphs

Answer 32

ml of urine per minute
S.G.
Chloride Concentration (mg/ml)

Question 33

What happens when we’re hydrated?

Answer 33

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

Question 34

What happens when we’re dehydrated?

Answer 34

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