1. Re-cap….
1. What are the 3 elements of the circulatory system?
2. Name the 3 types of blood vessels
3. In which direction do the arteries carry blood?
4. What type of blood do the arteries carry?
5. What substances are carried in the blood?
6. Explain homeostasis in one sentence
7. What substances/conditions need to be kept constant in the body?

2. Our bodies need to be kept in balance
this is called homeostasis
• Internal conditions which are kept in balance
are…
– pH
– Water content
– Ion (salt) content
– Temperature
– Blood sugar levels
How would variations in these levels affect your
body?

3. Lesson objectives
• All will know the names and parts of the
kidney system.
• Most will understand how the kidney works
and the process of selective reabsorption.
• Some will be able to apply their knowledge
and be able to analyse data on contents of
blood plasma and urine

4. The human kidney
1. The kidney is important for homeostasis. What substances does
the kidney remove and control? (3 marks)
2. Glucose are the subunits of carbohydrates. What makes up
proteins? (1 mark)
3. What is urea and why must it be removed from the body? (3
marks)
4. What does urine contain? (3 marks)
5. Your blood will continually pass through your kidneys where it is
filtered. This happens at a very fast rate. How long does it take for
all your blood to pass through your kidney? (1 mark)

5. Staying balanced - the kidney
• Where are the kidneys located?
– Humans have two kidneys
– They are bean-shaped
organs, approximately 11.5 cm
long, situated just below the
ribcage, one on either side of the
spine
• Label your diagram of the
kidney

6. What have you learnt?
1. What is urea?
2. What does urine contain?
3. Which vessel brings blood to the kidney?
4. Where is urine stored?
5. What is the name of the tube that carries urine
from the kidney to the bladder?

7. Lesson objectives
• All will know the names and parts of the
kidney system.
• Most will understand how the kidney works
and the process of selective reabsorption.
• Some will be able to apply their knowledge
and be able to analyse data on contents of
blood plasma and urine

8. The structure of the kidney

9. After the kidney dissection
1. Label the diagram of the
kidney
2. Explain what happens to
these substances in the
blood as it passes through
the kidney:
• Red blood cells (proteins)
• Urea
• Glucose
• Salts (ions)

10. Peer mark each others work
– Blood cells (proteins) too big to be filtered and
stay in blood (2)
– Urea filtered and none reabsorbed (2)
– Glucose filtered and all reabsorbed (2)
– Salts (ions) filtered and selectively reabsorbed (2)
What are the transport mechanisms involved in
reabsorption?

11. Lesson objectives
• All will know the names and parts of the
kidney system.
• Most will understand how the kidney works
and the process of selective reabsorption.
• Some will be able to apply their knowledge
and be able to analyse data on contents of
blood plasma and urine

12. Why are your kidneys so important?
1. The kidney is important in keeping conditions in the body constant –
what is this called?
2. What substance is removed by the kidney?
3. What is the name of the vessel that carries the blood to the kidney?
4. What happens to the blood as soon as it enters the kidney?
5. What is not filtered out into the kidney tubules?
6. How much glucose is reabsorbed into the blood?
7. How much water and mineral ions are reabsorbed into the blood?
8. What is the name of the vessel that carries the blood away from the
kidney?
9. What is the final product called once it has passed through the kidney
and out via the ureter?

13. Lesson objectives
• All will know the names and parts of the
kidney system.
• Most will understand how the kidney works
and the process of selective reabsorption.
• Some will be able to apply their knowledge
and be able to analyse data on contents of
blood plasma and urine