Activity:
Influence of Fluid Intake on Urine Formation
Name:
Miriam Rivera
Instructor:
Renee Faulcon
Date:
09.09.2014
Predictions
Urine output will be highest during water loading
Urine osmolarity will be highest during water loading
Plasma osmolarity increases with dehydration
Materials and Methods
Dependent Variable urine and plasma values
Independent Variable fluid intake
Controlled Variables room temperature, age, gender, and weight
4. Subjects were asked to refrain from alcohol and caffeine for a day before the start of the experiment. Explain why this is important.
Because alcohol and caffeine can dehydrate you very quickly
5. What technique was used to measure urine and plasma osmolarity?
30ml in 24hours
Results
Table 3. Urine Production Rate
Normal
42.5
1.9
13.8
Average
30 min (mL)
2.0
13.4
0.7
L/day
14.1
0.6
153.7
2.0
Dehydrated
30 min (mL)
L/day
0.7
158.3
149.8
7.2
7.4
2.0
0.7
Water loaded
30 min (mL)
7.6
38.6
0.7
Graph 1. Average Daily Urine Production Under Different Hydration States
1. Does dehydration increase, decrease, or not change average urine production rate (L/day).
Laboratory Report/ Miriam Rivera/ Influence of Fluid Intake on Urine Formation/ Renee Faulcon/ 09.09.2014/ Page [1] of [3]
L/day
40.4
1.9
7.4
7.4
decreased
2. Does water loading increase, decrease, or not affect average urine production rate (L/day). increased Table 4. Osmolarity (mosm/L)
630.5
1175.6
248.1
293.1
Normal
1237.3
154.9
288.2
299.0
Urine
Dehydrated
217.3
295.7
305
275.4
Water Loaded
295.4
301
276.2
206.8
Normal
291
275.2
609.1
293.1
Plasma
Dehydrated
274.8
575.7
1210.4
299.0
Water Loaded
621.2
1218.4
206.8
275.4
Graph 2. Blood Plasma and Urine Osmolarity Under Different Hydration States
3. Does dehydration increase, decrease, or not change average urine osmolarity (mosm/L)? increased 4. Does water loading increase, decrease, or not change average urine osmolarity (mosm/L)? increased 5. Does dehydration increase, decrease, or not change average plasma osmolarity (mosm/L)? decreased 6. Does water loading increase, decrease, or not change average plasma osmolarity (mosm/L)? decreased Discussion
1. State whether dehydration results in production of a concentrated or dilute urine.
Dehydration urine is concentrated. Because of the decreased urine
2. State whether water loading results in production of concentrated or dilute urine.
Water loading is diluted urine
3. Describe how ADH secretion during dehydration changes urine production and osmolarity.
This makes it so that you reabsorb more water from your urine back into your body
4. Describe how ADH secretion during water loading changes urine production and osmolarity.
When you are dehydrated, it usually means you don't have enough water and therefore your plasma volume decreases.
5. Describe how ADH secretion maintains plasma osmolarity levels during dehydration and water loading.
Maintaining plasma osmolarity is important for cell excitability and maintaining volume
6. Explain why in this experiment you did not see significant changes in plasma osmolarity during dehydration or water later loading. i saw a significant in water loading the numbers were doubled
Laboratory Report/ Miriam Rivera/ Influence of Fluid Intake on Urine Formation/ Renee Faulcon/ 09.09.2014/ Page [2] of [3]
7. Discuss why maintaining plasma osmolarity within normal limits is important.
This will make your blood pressure go up.
8. Restate your predictions that were correct and give the data from your experiment that supports them. Restate your predictions that were not correct and correct them, giving the data from your experiment that supports the correction. the predictions were correct
Application
1. Drinking alcoholic or caffeinated beverages increases urine output more than drinking an equivalent amount of water.
a. How do you think these beverages affect ADH secretion? those that contain caffeine or alcohol -- may actually cause, or worsen, dehydration
b. Would urine osmolarity be increased or decreased? it will increased
2. Explain why someone with diabetes insipidus must drink more water than normal.
The large volume of urine is diluted, mostly water. To make up for lost water, a person with diabetes insipidus may feel the need to drink large amounts and is likely to urinate frequently, even at night,
3. Explain what happens to plasma osmolarity when you give a severely dehydrated person large amounts of pure water.
The plasma will have a lower osmolality than 300 mOsm (more diluted) in particles due to the increase of water ingested
Laboratory Report/ Miriam Rivera/ Influence of Fluid Intake on Urine Formation/ Renee Faulcon/ 09.09.2014/ Page [3] of [3]