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

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

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. *

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

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

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

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

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