T2+Explanation+Respiratory+System

L.I. To write an explanation with a growing understanding of the deeper features & surface features appropriate to genre **Explanation - Audience Awareness & Purpose** S.C. I have indicated purpose & audience in my brainstorm S.C. I have used language appropriate to my target audience that is also linked directly with my explanation || **Features of an Explanation** ||
 * **Explanation**
 * The Workings of the Respiratory System.

Breathing air is neccessary to keep humans alive. The lungs are one of the largest organs in the human body. They work with the respiratory system to breathe in fresh air, oxygen and breathe out bad air, carbon dioxide.

Firstly, the mouth and nose let air into the lungs. The air goes from the mouth and nose down to the trachea and into the lungs. The nose has hair in it and together with mucus stops dirt and germs entering the lungs. The air then passes through the trachea or windpipe to the lungs. The trachea is very hard with tough rings around it. Only air goes into the trachea. Food and drinks use the esophagus. A special flap of skin covers the trachea which makes sure no food or drink gets into the lungs. Two bronchial tubes then carry the air on from the trachea to the lungs. One goes to the right lung, one to the left. The tubes then keep branching into smaller and smaller tubes until they reach tiny sacs at the end called alveoli. Bronchial tubes are covered in mucus which stick to dirt and germs. Millions of tiny hairs called cilia sweep back and forth about ten times a second, keeping things clean. Then when the air reaches the alveoli the really important jobs start. This is where the oxygen from the air enters the blood and the carbon dioxide leaves and is exhaled. There are around 600 million alveoli. Lastly all of this depends on a large sheet of muscle at the bottom of the chest cavity called the diaphragm. When the diaphragm moves down, the lungs breathe in. When it moves up, they breathe out. || **Identify Purpose/Audience** Purpose is to explain how the respiratory system works Audience, people wanting to find out information about the respiratory system e.g an asthmatic or student doing research

**< Heading **


 * 1) Statement or Question to be explained
 * How does the Respiratory System Work?


 * 1) Explanation arranged in sequence of steps
 * Why we breathe
 * What we breathe
 * How the respiratory system works
 * Lungs, ribcage, diaphragm, nose & mouth
 * Lungs, bronchus, alveoli, capillaries, blood
 * Breathe in Oxygen & breathe out Carbon dioxide
 * Keeping lungs healthy

**Time Connectives** First, Secondly, Then, Next

**Timeless present tense/Passive Voice** e.g. Oxygen then moves.. , Oxygen is breathed in the.. , Oxygen is pasted to the..,

e.g. When exercising breathing becomes more rapid
 * Exact details**

**Technical Terms Respiratory system, lungs, ribcage, oxygen, capillaries etc ** ||