Kidney
This worksheet is designed to be completed alongside the lesson.
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On average an adult produces enough urine in a day to fill a large fizzy drink bottle
– that’s 1.5 litres.
Where does all the urine come from? How is it produced? What is it made of and why must we get rid of it? You are going to explore the kidney and discover the answers to all these questions.
1
2
3
4
1. a. Describe how urine is moved down the ureter.
b. Why do you think urine does not leak from the bladder all the time? c. Look at diagram 1 at the end of the worksheet. On this diagram label the following parts:
2. a. Describe what happens to the renal artery after it reaches the kidney. b.
 urethra
 ureter
 bladder
 renal artery
 renal vein
 kidney
Use the data table to answer the following: i.
Name three substances found in urine. ii.
Name two substances found in the blood but not in urine. c. Suggest where the urine in the kidney pelvis has come from.
3. Use the data table to state what happens to the amount of urea, water and ions dissolved in the blood as it passes from the renal artery to the renal vein.
4. a. Look at diagram 2, which shows parts of the kidney tubule. i.
Add red arrows to show the path taken by the blood. ii.
Add yellow arrows to show the path taken by the contents of the tubule from the Bowman’s capsule to the kidney pelvis. b. How can you tell from the data that the substances found in the urine have come from the blood as it passes through the kidney?
Copyright © 2004 PLATO Learning (UK) Ltd. All rights reserved.
Multimedia Science School range of software is distributed by RM under licence from PLATO® Learning, Inc.

Kidney
5 c. How do you think the position of the tubules and blood vessels might help substances move from one to the other?
5. a. Complete the table by adding a tick in the correct column next to each substance (to indicate whether it is filtered or not filtered from the blood).
Filtered Not filtered
Blood cells
Urea
Blood proteins
Water
Ions
6
Glucose b. Why do you think some substances cannot be filtered from the blood? c. Which substance is filtered from the blood but is not found in urine? d. Use the data table to answer the following questions: i.
How much water is filtered from the blood per day into the capsule? ii.
Suggest where the filtered substances would go if they continued to the end of the tubule. iii.
We only lose 1500 grams of water in urine each day. Where do you think the other 178 500 grams of water that is filtered into the capsule goes?
6. a. Describe what is happening to the filtered substances as they move along the tubule. b. i.
Which of the filtered substances are completely reabsorbed back into the blood? ii.
Which of the filtered substances are mostly reabsorbed back into the blood? iii.
Which of the filtered substances are only slightly reabsorbed back into the blood?
Copyright © 2004 PLATO Learning (UK) Ltd. All rights reserved.
Multimedia Science School range of software is distributed by RM under licence from PLATO® Learning, Inc.

Kidney
7
8 c. Complete the following sentences using the words in the box:
Blood enters the kidney in the renal ______, carrying dissolved glucose, urea, blood proteins and ______.
The artery branches into capillaries in the outer part of the kidney and the blood passes through tiny capillary ‘knots’. These glomeruli are surrounded by hollow ______. Here toxic urea and a great deal of water, ions and glucose are ______ from the blood.
As the filtered substances pass along the tubule, the glucose and most of the water and ions are ______ back into the blood.
Then urea and other substances that have not been reabsorbed from the tubule into the blood drain down ducts into the ______.
This urine is squeezed down the ______ into the ______. filtered capsules artery kidney pelvis ureter bladder reabsorbed
ions
7. a. i.
When we are dehydrated what happens to the amount of water being absorbed? ii.
When we are dehydrated what happens to the amount of water reaching the bottom of the duct? b. Explain why we produce a small amount of dark-coloured urine when we have been sweating. c. Explain why we produce lots of pale-coloured urine after drinking water.
8. a. i.
Explain why the blood concentration changes shortly after you drink water. ii.
Explain why the blood concentration changes shortly after you begin to sweat. b. Describe what happens to the amount of ADH released as the blood concentration varies. c. What is the effect of low levels of ADH on the amount of water that is reabsorbed from the tubule? d. In what way will this change in reabsorption affect: i.
the concentration of the blood? ii.
the amount and colour of the urine produced?
Copyright © 2004 PLATO Learning (UK) Ltd. All rights reserved.
Multimedia Science School range of software is distributed by RM under licence from PLATO® Learning, Inc.

Kidney e. Complete the following flow diagram with the words ‘increases’ and ‘decreases’.
Drink water
Water enters blood in digestive system
Blood concentration ________
ADH level ________
Amount of water being reabsorbed ________
Urine amount ________ and colour becomes pale
Blood concentration ________ f. Draw a similar diagram to show what happens when we lose water from the blood by sweating.
Copyright © 2004 PLATO Learning (UK) Ltd. All rights reserved.
Multimedia Science School range of software is distributed by RM under licence from PLATO® Learning, Inc.

Diagram 1 (question 1c)
Diagram 2 (question 4a)
Kidney
Copyright © 2004 PLATO Learning (UK) Ltd. All rights reserved.
Multimedia Science School range of software is distributed by RM under licence from PLATO® Learning, Inc.