Homeostasis experiment Free Essay Example

Does the concentration of the solution that one drinks affect the rate of urine production?

To investigate this we have to use different solutions of water; varying salt concentrations on various subjects. Four days were set for the experiment. The first day subjects would drink normally, but come and urinate in a beaker so as to measure how much urine has been discharged. The second day a distilled amount of water was given to the subjects- they would come in the morning (9 AM) to drink a liter that water and we’d then measure how much urine came about each time they came to urinate until 1530 (time school is out).

The third day the same thing was done but with a liter of .9% concentration of salt. The last day of the experiment the subjects drank each one of three different mineral waters- to see their effect on homeostasis.

Hypothesis: As salt is water retaining- The subjects would urinate much less on days where they drinks salt water then on days where they drink distilled water or normal water- as they would urinate much more on days where they would drink distilled water than on normal days and days where they’d drink salt water.

Results:

Type of solution

Urine production

Total output

Urine output,

drunk

time given and volume mls

mls in a day

Mls per hour

Control:

Normal intake

Sub. 1. 12:20 90

try 1

15:30 110

200

31

sub. 2 14:00 280

15.30 150

320

51

Sub. 3 12:20 140

15:30 90

230

35

Try 2

sub 1 12:20 180

15:30 110

290

45

sub. 2 13:00 280

15.30 150

430

66

Sub. 3 12:00

15.30 130

400

62

Average

311.66

48.3333

1 Liter of dist.

Sub 1. 9.30 100

1050

162

water at 9.00

10.30 410

try 1

11.30 340

15.30 200 (estimated)

Sub.2 10.40 510

1420

218

11.40 610

15.30 290

sub 3 11.40 490

770

118

15.30 280

Try 2

sub.1 9.30 200

1150

177

10.30 410

12.00 340

15.30 200

1280

197

Sub 2. 11.00 520

12.40 510

15.30 250

sub 3. 11.40 490

1070

165

13.30 300

15.30 280

Average

1123.333

172.8333

1 liter of 0.9%

salt at nine

sub 1. 1530 370

370

57

sub 2: 1110 390

740

114

15:30 350

sub 3 12.00 270

420

67

15:20 150

Average

510

79

Mineral waters

Contrex

Sub 1.

12.30 370

15:30 320

690

106

Volvic

Sub.2 12:10 490

15.20 380

870

137

Evian

Sub.3 10.00 370

12.00 420

15.30 250

1040

160

Data analysis:

We observe that the average for the normal intake is rather strange. One would predict it to be in between the average values for the distilled water, and concentrated water; instead it is much closer to the concentrated water average. This shows that the liquid intake of students is either quite low normally, or highly concentrated in water retaining nutrients. Though on the second try to obtain readings for normal intake the numbers marked were yet much lower; this suggests there can be another factor is playing a role in the urinating.

Regarding the distilled water; all readings mark over 1000 mls of urine excreted in six hours- except for one which is that of subject 3, marking a reading of 700. This shows the hypothesis to be right. The reason for which water had to be released so much that day is because the distilled water didn’t hold any nutrients or minerals- which ended up diluting the plasma in the blood. The excess water is taken out- so as to hold homeostasis.

When the body has a high count of salt the liver tries to hold enough water to dilute the salt- thus the urine count would go down. This is what the hypothesis was based on, and it was shown to be right by the results- except for subject 2 who had a urine count of 740 mls for a day. What is especially disturbing is that the average is higher than that of the normal water intake average. This either means that the drinks drunk on normal days are highly water retentive- or that the diets are high in minerals and nutrients that are water retentive- not healthy.

The contrex drinking subject showed to have least urinated. This shows that all things held constant- the contrex water is high in minerals that are water retentive. Evian was the least water retentive- and volvic was in between. This shows that contrex was most concentrated, evian was most diluted and volvic was in between.

Discussion:

There is a main problem- that is the control of the diet. It wasn’t thought of that maybe the students would be eating foods that are high in minerals that retain water; such as salts. Food today is not that healthy and most contains high counts of salt. The subjects should’ve had the same diet. This something else that is a problem- we do not know if they had a similar diet or not. The subjects were also only made to drink the given type of water in the morning, and only a liter. That might not be sufficient for the experiment to be conducted correctly. What should’ve been done is that every time they needed to drink water they’d drink the water type that was subject of the experiment for the given day.

Women are able to hold more urine than men- two sets of results should’ve been made, one with female participants and one with male participants. Sports is also another problem, the more someone is active, the more that person sweats- the more the sweat, the less water in the body- meaning more water retention translating to less urine. Activity should’ve been controlled as well. Finally- the subjects should’ve been subject to the different water intakes for more than six hours- they should’ve been given the different types of water for at least 24 hours at a time. A follow up experiment would take into account all the criticisms.

Conclusion:

The hypothesis was proven right- although the experiment should’ve been more controlled in order to have more precise and real results.