You are a veterinarian working in Indooroopilly and return from lunch to find a nurse treating a six year old kelpie, Baxter.
Baxter is very lethargic, has an increased heart rate, and when you pinch his skin the fold remains visible. The owner tells you that they knew something was wrong when, upon returning to the outdoor car park from a three hour shopping trip, they saw Baxter passed out on the back seat. The temperature in the car would have been very high and Baxter will have lost a lot of water through evaporation as he panted to stay cool. This loss of water would have reduced his blood volume, thereby increasing the concentration of the ECF.
This is the hypotheses that you developed before conducting your experiment.
It is hypothesised that when sheep’s RBC are added to a hypertonic solution, they will shrivel and occupy less space within a haematocrit tube, when compared to a hypotonic solution that will cause the cells to lyse.
Materials and methods
This is the description you gave of the materials and methods you used to test your hypothesis.
We started by using a weighing scale to measure 5.84 grams of Sodium Chloride, which was mixed with
100ml of deionised water in a 100mL Volumetric Flask. We then used the appropriate pipette and pipette tips (100µL and 1000µL) to mix our NaCl solution with deionised water to create our 5 different concentrated solutions. The solutions were mixed in 5 different test tubes and were held in a test tube rack.
Using a 1:4 ratio we pipetted 200µL of 150mM Sheep’s RBC (Red Blood Cells) and 800µL of each of our 5
NaCl solution into 5 separate centrifuge tubes. After twirling the centrifuge tubes we took a sample of our solutions using five 75 mm Haematocrit tubes that were sealed using Hawksley cristaseal. These samples were put in a Haematocrit centrifuge 1000RPM for 3 minutes. Once complete the percentage of live cells in the haematocrit tubes was examined
References: List any references you have used in the panel below: About.com, 2013, Osmosis Blood Cells, online, available at: http://chemistry.about.com/od/imagesclipartstructures/ig/Science-Clipart/Osmosis---Blood-Cells.htm Encyclopedia of Nursing & Allied Health, 2002, Dehydration. Ed. Kristine Krapp. Vol. 2. Gale Cengage, Available at: http://www.enotes.com/dehydration-reference/ ©2008-2013 ADInstruments