BIOS256 Week 4 Lab: #10 Influence of Fluid
Intake on Urine Formation Laboratory Report
Activity 10: Influence of Fluid Intake on Urine Formation
Name: Shamir Tyson
Instructor: Professor Shen
Date: November 24, 2013
PREDICTIONS
1. Urine output will be highest during: Water Loading
2. Urine osmolality will be lowest during: Dehydration
3. Plasma osmolality: increases with dehydration
METHODS AND MATERIALS
1. Dependent variable: Urine and plasma values
2. Independent variable: fluid intake
3. Controlled variables: age, gender and weight/ Room temperature
4. Subjects were asked to refrain from alcohol and caffeine for a day before the start of
the experiment. Explain why this is important. This is important as caffeine and alcohol
could affect the outcome of the experiment especially these products could cause
excretion of urine since they are diuretics and effect plasma work.
5. What technique was used to measure urine and plasma osmolality? The centrifuge was
used to separate the plasma. The plasma and urine was then refrigerated and later
accessed and placed in the osmometer for results
RESULTS
See Table 3: Urine Production Rate
See Graph 1: Average Daily Urine Production Under Different Hydration States
Type in the following AVERAGE urine production rate (L/day)
• Normal
, • Dehydrated
• Water Loaded
Normal Dehydrated Water Loaded
Subject 1 1.98 0.63 7.59
Subject 2 1.96 0.62 7.18
Subject 3 1.82 0.64 7.48
Average 1.92 0.63 7.42
1. Does dehydration increase, decrease, or not change average urine production rate
(L/day)? Dehydration decreases urine production
2. Does water loading increase, decrease, or not affect average urine production rate
(L/day)? Water loading increases the urine production rate
See Table 4: Osmolality (mosm/L)
See Graph 2: Blood Plasma and Urine Osmolality Under Different Hydration States
Type in the following AVERAGE urine osmolality (mosm/L)
• Normal
• Dehydrated
• Water Loaded
Urine
Normal Dehydrated Water Loaded
Subject 1 630 1250 188
Subject 2 585 1180 188
Subject 3 621 1170 162
Average 612 1200 179
3. Does dehydration increase, decrease, or not change average urine osmolality
(mosm/L)? Dehydration increases urine osmolality
4. Does water loading increase, decrease, or not change average urine osmolality
(mosm/L)? Water loading decreases urine osmolality
Type in the following AVERAGE plasma osmolality (mosm/L)
Intake on Urine Formation Laboratory Report
Activity 10: Influence of Fluid Intake on Urine Formation
Name: Shamir Tyson
Instructor: Professor Shen
Date: November 24, 2013
PREDICTIONS
1. Urine output will be highest during: Water Loading
2. Urine osmolality will be lowest during: Dehydration
3. Plasma osmolality: increases with dehydration
METHODS AND MATERIALS
1. Dependent variable: Urine and plasma values
2. Independent variable: fluid intake
3. Controlled variables: age, gender and weight/ Room temperature
4. Subjects were asked to refrain from alcohol and caffeine for a day before the start of
the experiment. Explain why this is important. This is important as caffeine and alcohol
could affect the outcome of the experiment especially these products could cause
excretion of urine since they are diuretics and effect plasma work.
5. What technique was used to measure urine and plasma osmolality? The centrifuge was
used to separate the plasma. The plasma and urine was then refrigerated and later
accessed and placed in the osmometer for results
RESULTS
See Table 3: Urine Production Rate
See Graph 1: Average Daily Urine Production Under Different Hydration States
Type in the following AVERAGE urine production rate (L/day)
• Normal
, • Dehydrated
• Water Loaded
Normal Dehydrated Water Loaded
Subject 1 1.98 0.63 7.59
Subject 2 1.96 0.62 7.18
Subject 3 1.82 0.64 7.48
Average 1.92 0.63 7.42
1. Does dehydration increase, decrease, or not change average urine production rate
(L/day)? Dehydration decreases urine production
2. Does water loading increase, decrease, or not affect average urine production rate
(L/day)? Water loading increases the urine production rate
See Table 4: Osmolality (mosm/L)
See Graph 2: Blood Plasma and Urine Osmolality Under Different Hydration States
Type in the following AVERAGE urine osmolality (mosm/L)
• Normal
• Dehydrated
• Water Loaded
Urine
Normal Dehydrated Water Loaded
Subject 1 630 1250 188
Subject 2 585 1180 188
Subject 3 621 1170 162
Average 612 1200 179
3. Does dehydration increase, decrease, or not change average urine osmolality
(mosm/L)? Dehydration increases urine osmolality
4. Does water loading increase, decrease, or not change average urine osmolality
(mosm/L)? Water loading decreases urine osmolality
Type in the following AVERAGE plasma osmolality (mosm/L)
