Osmoregulation Lab - Observing Osmoregulation

Observing Osmoregulation

Introduction: The main function of the kidney is to regulate the osmolality of the body’s fluids. In this lab, students observe osmoregulation by testing urine samples. The students divide into three groups. Each group drinks 800 ml water, 800 ml Gatorade, or 7 grams of NaCl with 80 ml of water. The students then record the average volume of urine produced, the specific gravity of the urine, and the NaCl level of the urine.

Data:

Graph 1

Graph 2

Graph 3

Observation:

Graph 1 shows the average volume of urine secreted by each student. Overall, the NaCl group’s urine volumes decreased throughout the experiment. The average volume of the Gatorade and the water increased throughout the experiment, but declined at the end. Water had the highest peak of urine amount, yet the amount of urine decrease more rapidly than the Gatorade group.

Graph 2 shows the specific gravity. The NaCl group had high specific gravity levels through the experiment. The water group had nice “bell curve” results. The water group’s specific gravity went lower then the Gatorade group and increased more rapidly.

Graph 3 displays the NaCl levels in the urine of each group. As expected, the NaCl group had the highest level of NaCl throughout the experiment. At the beginning of the experiment the Gatorade group had more NaCl, but eventually the water group levels rise higher than the Gatorade group. In the end, the water and the Gatorade groups end up with the same levels of NaCl.

Discussion:

The average volume of urine produced by the water group was expected to be high because the water consumed contained no salts whatsoever, whereas the Gatorade contains high levels of salt,