Respiratory System /Air

1. Human

1.1. Nose:The fine hair in the nose traps dust that is in the air we breathe in.

1.2. Windpipe:The windpipe is the main air tube that branches into many other smaller air tubes.

1.3. Lungs:We have two lungs that have many blood vessels.

1.4. Diaphragm:When you breathe in,your ribs move out and outwards.When you breathe out, your ribs move in and inwards.It is also a thin sheet of muscle.

2. Animals

2.1. Fish:Carbon dioxide passes through the walls of the blood vessels ,dissolves in the water and is carried away as the water flows out from under the gill cover.

2.2. Mammals:Mammals breathe through lungs.

2.3. Insects:Insects breathe through spiracles.

3. The mixture of nitrogen,oxygen,carbon dioxide,water vapour and other gases is called air.

4. When air moves, that movement is called wind.