When air enters the lungs, it travels down the bronchus, which divides like a tree, which gets smaller and smaller. At the end of each tiny branch, or bronchiole, is a structure called alveoli. Alveoli are like little balloons of air sacks. Alveoli are full of oxygen-rich air that has been drawn into the lungs during inspiration. This oxygen needs to get into the blood, so that the cardiovascular system can fulfil its role of transporting the oxygen to the working cells. This movement of oxygen takes place in the alveoli, where a capillary can always be found close by, and the oxygen can move from one place to another that is from the lungs into the blood. The capillary that is close to the alveoli is carrying the blood that has been pumped from the body via the heart. It is carrying a lot of carbon dioxide. The carbon dioxide move from the blood into the alveoli, at the same time that the oxygen is moving in the other direction. This process is known as gaseous movement. The movement of oxygen from the alveoli to the blood can be less efficient if the person is suffering from a respiratory disease, and has built up in the lungs.
1) Explain the term Inspiration
2) Explain the term Expiration
3) Draw a flow diagram of the sequence of events that occurs during expiration.
4) Draw a simple sketch of the size of the rib cage and diaphragm at the start of inspiration, and at the end of inspiration.
5) What effects does the size of the lungs have on the movement of air into and out of the lungs?
6) Why is it important that the suction between lungs and the ribs is maintained?
7) Using a blank diagram label the structures of the respiratory system.
8) Refer to the cardiovascular system and suggest where the heart would be positioned on your diagram.
9) What happens to the dust that is filtered out of the nasal passage