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?

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?

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

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)

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

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?

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

The structure of the kidney

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)

– 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?

Peer mark each others work

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

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?

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