Urinary System Anatomy and Physiology Urinary System Anatomy I. Kidney dissection a. Find the following structures in the dissected sheep or pig kidney. To dissect, cut the kidney through the midsagittal plane producing left and right mirror images. i. Ureter ii. Renal capsule iii. Hilum iv. Renal sinus v. Renal pelvis vi. Calyx(ces) vii. Renal cortex viii. Renal medulla ix. Renal column x. Renal pyramids xi. Renal artery xii. Renal vein xiii. Interlobar artery xiv. Interlobar vein xv. Interlobular artery xvi. Interlobular vein II. Figure review a. Review the figures provided in the lab PowerPoint and identity all labeled areas b. Use these figures to identify the structures on the kidney models provided. Urinary System Physiology Experiment I: Demonstrate the movement of materials from the blood to form urine. (Completed by the Instructor) We will use a piece of dialysis tubing. This is a thin, polymer tube containing many microscopic holes that allow very small ions to pass through. This will represent our glomerulus filtering into Bowman’s capsule. Your instructor placed a blood sample into dialysis tubing. The tubing was then placed in water. Components of the blood will slowly filter out and form urine. Record your conclusions on the answer sheet below. Experiment II: Demonstration of Dialysis This lab demonstrates a very simple dialysis system. Although the dialysis which this system performs is much simpler than that used in patient hemodialysis, all the concepts and components are represented. 1. Obtain a piece of dialysis tubing and tie a knot in one end to form a bag. (Make sure to follow instructor’s demonstration) 2. Add to the dialysis bag one pipette volume each of: 10% sodium chloride solution (NaCl) and 1% egg albumin solution 3. Eliminate as much as possible from the fluid space, and tie off the open end of the dialysis bag tightly with a piece of string. Then mix the contents. Rinse the closed dialysis bag under tap water and blot the exterior of the bag with a paper towel to remove excess water. 4. Weigh your dialysis bag and record its initial weight: ________. Then place it in a beaker of distilled water so that it is completely covered by water. Gently shake the beaker occasionally to promote better diffusion. Note the time. Continue with other lab activities while you allow dialysis to proceed for at least an hour. 5. After an hour, remove the dialysis bag, shake off external water, lightly blot it dry with a paper towel, and record its final weight: ______ 6. To analyze the presence of albumin (protein) that has diffused out of the tubing, pipette a sample of the contents of the beaker into a test tube. Next, pipette a sample of the contents of the dialysis tubing into another test tube. Only a few ml are needed in the test tube. Do not fill the test tube more than 1/4 full. 7. Add 4 drops of biuret reagent to the test tubes from #6. The formation of a pink to violet color is a positive test for the presence of protein such as albumin. Compare the test sample to test tube of water treated in the same manner. 8. Record your results in Table 1 on the lab assignment sheet to be turned in for grading. Experiment III: Demonstration of Urinalysis Urinalysis, the physical, chemical, and microscopic analysis or examination of urine, provides information about patient carbohydrate metabolism (diabetes), kidney and liver function, acid‐base balance, and urogenital tract infections. We will use reagent strips which measure pH and the concentrations of several clinically significant components of urine. Some of the substances measured, such as protein or glucose, are rarely if ever present at detectable levels in the urine of healthy patients. Other parameters, such as pH, fluctuate over a wide range depending on diet, health status, and fluid intake. The table below presents expected normal test values and explains the significance of each parameter measured. The examples provided represent only some of the possibilities. The following web link provides a good summary of urinalysis: 1. Take a urine specimen cup to the bathroom and obtain a urine sample. Return to lab (or complete in bathroom) and measure the following properties of the urine specimen using your own visual and olfactory faculties as well as urinalysis sticks. 2. Record and analyze your results in table 2 below using the following information. Property leukocytes Nitrite pH Expected range clear to amber transparent, not cloudy (not turbid) slightly aromatic, but not fruity or like acetone, no ammonia negative‐trace negative 4.6‐8.0 Protein Glucose Ketones negative‐trace negative negative‐trace Color turbidity Odor urobilinogen 0.2‐1.0 normal bilirubin 0.1‐1.0 Blood negative Significance of positive test (or abnormal range) redness due to blood from glomerular injury, infections turbidity due to possible infection ketosis, possible infection urinary tract infection associated with some bacterial infection continuously very acidic urine may indicate acidosis; continuously very alkaline urine may indicate alkalosis or microbial infection. excessive glomerular permeability, glomerulonephritis positive suggesting possible diabetes mellitus diabetes mellitus, starvation, pregnancy, frequent/recent strenuous exercise liver dysfunction, hemolytic diseases high: hemolytic or pernicious anemia, liver dysfunction inflammation/injury of urogenital tract or kidneys, menstrual contamination Name:_____________________ Lab Day and Time: _______________ Experiment I: 1. What components of blood are filtered into the water to produce urine? 2. What force is driving the movement of materials into the water and out of the blood? 3. Is it possible for a material in the water to move into the blood? Why? Table 1: Dialysis Results Dialysis bag weights: Initial: Final: 1. What did the protein analysis of the water in the beaker reveal? Did protein move out of the tubing? 2. What did the change in weight reveal? Which way did the water move? 3. How does this demonstrate tubular absorption or secretion? 4. How does this relate to the process of hemodialysis? Table 2: Routine Urinalysis Circle the appropriate result and check the third column is the result was abnormal. Property Description (circle your result below, then indicate if the result is abnormal (√) in the column to the right) color clear, pale straw, light yellow, light amber, dark amber, red, other (indicate) turbidity transparent, cloudy (= turbid) odor aromatic, sweet or fruity, ammonia, foul leukocytes negative, trace, + small, ++ moderate nitrite negative, positive pH 5.0, 6.0, 7.0, 8.0, 9.0 protein (mg/dL) negative, trace, + 30, ++ 100, +++ 500 glucose (mg/dL) normal, 50, 100, 250, 500, 1000 ketone (mg/dL) negative, + small, ++ moderate, +++ large urobilinogen (mg/dL) normal: 0.2 ‐ 1; abnormal: 4, 8, 12 bilirubin negative, + small, ++ moderate, +++ large blood (eryth/microL.) non‐hemolyzed: neg, trace, moderate, or hemolyzed: trace, small, mod. large √ = abnormal
Briefly describe the results below in a paragraph. Discuss any abnormal results and possible causes. Materials List: Urinary System Copy handouts and provide PowerPoint files Copy any preliminary information on diffusion/transport Dissection: 
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Dissection trays (1 per group) Dissection tools (1 each per group) Kidneys (1 each per group) Experiment 1: 
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Dialysis tubing (1 for instructor) Simulated blood (10 mL per lab) Experiment 2: 
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Dialysis tubing (1 per group) 10% NaCl solution (5 mL per group) o 10 g/100 mL 1% albumin solution (5 mL per group) o 1 g/100 mL 1000 mL beaker (1 per group + 1 for instructor) Analytical balance Biuret reagent (<1 mL per group) Plastic transfer pipettes Experiment 3: 
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Urinalysis sticks (1 per student or group) Cups for urine collection (1 per student or group) Easy Modifications to Urinary Anatomy & Physiology Lab Experiment 
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Animal kidneys for dissection not available o An understanding of the anatomy is essential to the physiology experiment. However, if a kidney is not available, remove the kidney dissection slides from the PowerPoint file and use models or figures available to discuss the important anatomy. Blood not available o I typically use blood purchased from Ward’s (cat. No. 36 W 0039), but any unfiltered blood will work adequately. If no blood is available, fake blood can be made by using a solution of cytochrome c and yellow food coloring. Simply dissolve the cytochrome c and yellow food coloring in water to a concentration that gives a nice red color. The red color will not be able to diffuse through the dialysis tubing but the food coloring will diffuse through the dialysis tubing. The dialysis tubing must have a very small pore size so this should be attempted using the available tubing before presenting to the class. Urinalysis Sticks not available o The urinalysis sticks used for the experiment are relatively inexpensive. I use Chemstrip 9 from Roche (cat. No. 417109). However, if the budget is a problem there are alternative sticks available at discount stores such as Wal‐mart. These sticks will not give results for all the tests described, but they can look at the levels of glucose in the urine and relate this to glomerular filtration. Also, litmus paper to observe the pH of the urine and biuret reagent to observe presence of protein in the urine can be used. Only diffusion experiment is affordable o If only the diffusion experiment portion with the dialysis tubing is being completed, give each student a different concentration of salt and protein. This will allow some students to observe movement into the tubing, while other students observe movement out of the tubing. In this experiment, both adsorption and secretion can be related. Common Problems with the Experiment 
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The diffusion experiments involving dialysis tubing can take some time to complete. I will often begin these experiments before a complete explanation. It is important to finish all explanations before the results are observed. I have in the past allowed students to observe their urine under the microscope as part of this lab. However, I had a student with an observable STD in the past. This is uncomfortable to explain when the students begin asking what they are observing. Often students have inadequate knowledge entering the experiment. I often will review diffusion and osmosis prior to the lab.