1. Excretory System
Introduction & Kidney

2. Video

3. Remember
Recall that the numerous reactions take place in the cells in the body
These chemical reactions that take place within the body which are necessary for the maintenance of life are known as metabolism
Metabolism produces metabolic wastes.

4. Wastes that chemical reactions produce:
These chemical reactions produce numerous waste products. For example:
Carbon dioxide (from respiration)
Excess water (from respiration)
Urea (breakdown of proteins)
Bile pigments (breakdown of red blood cells)

5. The Excretory System of Human Beings
Human beings have an excretory system which consists of:
Kidneys
Skin
Liver
Lungs

6. Note Well
Excretion must not be confused with the removal of the faeces, that is defaectaion from the anus
Defaection refers to the removal of undigested food from the body through the anus
However, excretion refers to the removal of the waste products of metabolism of the body

7. Diagram of the Human Excretory System

8. Parts of the excretory system
Kidney
Ureter
Bladder
Urethra

9. Kidney – 3 main parts cortex, medulla, pelvis

10. Functions of the kidney
Filter waste materials from the blood
Controls the amount of water in the body