1. Respiration and Excretion
Alveoli
The kidneys
Nose
The trachea
Bronchus
Lungs
Ureter
Bladder
The diaphragm
Urethra

2. Respiration: Oxygen is essential for life we need it to obtain energy from nutrients. We obtain oxygen from the air we breath. This is how:
Inhalation: the thorax expands and air enters the body
The nasal cavity: air goes through the nose to the naval cavity where it becomes warm, moist and cleaner
The Nose: air enters the body through the nose and mouth
The Trachea: connects the nose with the lungs. It divides into two bronchi
The Lungs: two spongy, elastic organs protected by the sternum and ribs.
Air passes into the blood through the lungs
Alveoli: exchange point for oxygen and carbon dioxide
Exhalation: the thorax contract and air is expelled from the body

3. To keep our respiratory system healthy we should avoid harmful *
Respiration and health: The air we breath contains oxygen which is vital for us to breath. How ever, that air can also contain substances that are harmful. Which means it can be contaminated.
These substances are:
Polution: from cars, heating and factories
Toxic Substances: found in glue, paint and cleaning products
Cigarette Smoke: contains toxic ingredients and is very harmful
To keep our respiratory system healthy we should avoid harmful
substances and breath clean air. *

4. Nutrition and excretion
Waste substances are produced during the process of nutrition
We eliminate them through excretion
The cleaning of the blood takes place in the excretory system
This also takes place in our skin through the process of sweating

5. The excretory system
Kidneys – these are the main organs in the excretory system, they filter the blood and make urine
The bladder – this is the organ where urine is stored until it is expelled from the body
Urethra – this is the tube through which urine is expelled

6. All the blood in our body passes through the kidneys
The kidneys act like sieves that filter the blood
They trap water and waste substances and return clean blood to circulation
The water and waste substances trapped in the kidneys make up urine
Urine travels to the bladder through tubes
It is stored in the bladder until it is expelled through the urethra

7. Sweat
The main job of sweat is to keep our body cool when it gets too hot
Sweat also helps to keep our blood clean
Sweat contains...
Water
Mineral salts
Waste substances

8. Excretion and health Drink enough water Water is essential to our body
We lose a lot of water when we expel urine and sweat and we have to replace it by drinking enough
Keeping our skin clean
Taking daily showers
Washing our hands
frequently