BIOS256 Week 4 Lab 10: Influence of Fluid Intake on Urine Formation

BIOS256 Week 4 Lab: #10 Influence of Fluid Intake on Urine Formation Laboratory Report

Activity 10: Influence of Fluid Intake on Urine Formation

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.
Alcohol and caffeine will increase the amount of urine output

5. What technique was used to measure urine and plasma osmolality?
Water consumption measured urine output, and a finger stick. An osmometer was used to check osmolarity.

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
1.88
.78
7.07
Subject 2
2.02
.76
7.54
Subject 3
2.12
.61
6.3
Average
2.01
.72
6.979

1. Does dehydration increase, decrease, or not change average urine production rate (L/day)? Decreases production

2. Does water loading increase, decrease, or not affect average urine production rate (L/day)? Increase production

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
578
1190
187
Subject 2
593
1170
182
Subject 3
633
1210
199
Average
601
1190
189

3. Does dehydration increase, decrease, or not change average urine osmolality (mosm/L)? Increases