Respiratory System

1. Air is made up of about 78% nitrogen, 21% oxygen, 0.03% carbon dioxide and 0.97% of others.

2. Oxygen

2.1. It is a chemical reactive gas. plants and animals take this in for respiration. It is produced during photosynthesis and it is needed for burning.

3. Nitrogen

3.1. It is the most abundant gas and it does not support burning.

4. Carbon Dioxide

4.1. It is produce when living things respire and when things burn and decay. It is present in a variety of carbonate materials and rocks. Plants take this in during photosynthesis.

5. This system is made up of 4 parts for the humans.

5.1. Nose

5.1.1. Windpipe

5.1.1.1. Lungs

5.1.1.1.1. Air sacs

5.1.1.1.2. Contains air sacs. Allows exchange of gases in the air sacs.

5.1.1.2. Transfer the air from the nose to the left and right lungs.

5.1.2. Allows air to enter and leave the body. Contains hair and mucus to trap the dirt in the air.