You will find the kidney animation linked on my blog: mskjcrowley.wordpress.com

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1 Name: SBI4U Nephron Quest To do this task you will need; this worksheet, something to write on, something to write with and the kidney flash movie. You will find the kidney animation linked on my blog: mskjcrowley.wordpress.com Work through the tasks along with the worksheet. If something goes horribly wrong you can use the drop-down list control at the top right of the screen to restart a section. Make good use of the pause button if things are going too fast for you. Section One The Kidney 1. Explore the animation using your mouse pointer. Record in the table below the name of each labelled structure and its general function. A B E D C F A B C D E F

2 Section Two The Nephron Click on the continue button to see what a nephron looks like and where it is placed. Click on the nephron and record below the names of each section of the nephron: 2. Now you are going to find out what happens to our five important substances as they enter in the arterial blood vessels. Click on the Urea check box and a urea molecule will appear. Click on the start button and follow its route. Remember that you can pause at any time and watch it again by clicking on start when the check box is selected. Uncheck the urea and repeat the procedure with each of the other substances. For each substance, list (in order) all the structures of the nephron that each passes through, and if/when it is filtered, reabsorbed, or secreted. Also, suggest a possible reason for the behaviour of each substance. Urea: Glucose: Water: Protein: Sodium:

3 You are now going to find out about the processes that happen in each part of the nephron leading to the behaviours you observed, in the order in which they take place. Section Three The Renal Capsule (The Bowman s Capsule) Look carefully at the renal capsule. It contains many capillaries surrounded by a cup-shaped wall that connects with the nephron s tubule. Now click on the renal capsule to watch an animation. The animation shows a greatly magnified section through one capillary and the capsule wall near to it. 3. Why do you think blood protein (plasma protein) is not filtered out of the blood and into the capsule? 4. Suggest which of the three layers separating the blood from the fluid in the tubule actually carries out the filtering. Section Four The Proximal Convoluted Tubule Go back to the nephron and then click on the proximal convoluted tubule. 5. Use the mouse pointer to examine the transport proteins. Fill in the table below with which substances are reabsorbed back into the bloodstream. Substance Urea Glucose Water Sodium Protein Reabsorbed (YES/NO) 6. Why is this part of the nephron selective?

4 Section Five The Loop of Henle Go back to the nephron and then click on the loop of Henle. Watch the animation a few times to get a feel for the sequence that takes place as fluid passes through it. You should use the pause button to help you read the steps. 7. Describe what happens in both the descending and ascending limbs. 8. What does the loss of water from the filtrate cause? To find out more about one of the functions, click on the loop to launch an animation that shows how the loop develops a salty medulla layer. 9. What do you notice about the fluid concentration entering the loop and the concentration as it leaves? 10. What happens if you increase the sodium concentration entering the loop? 11. Desert mammals have particularly long loops. Suggest the advantage for this.

5 Section Six The Distal Tubule There is no animation for the distal tubule. Using your notes, record which substances are secreted and reabsorbed in this section of the nephron. For each substane, state whether it uses active or passive transport. Section Seven The Collecting Duct Go back to the nephron and then click on the collecting duct. 12. What substances leave the nephron through the collecting duct? 13. ADH (Antidiuretic Hormone) is a hormone that causes what to happen? 15. In what situation(s) do you think our bodies need to release ADH?