1. Respiratory System

2. Respiratory System – gas exchange Path of the Respiratory System: Air enters the mouth or nose Air continues down the pharynx past the larynx (voice box) and into the trachea (windpipe) The lower end of the trachea splits into 2 bronchi

3. The bronchi split off into several bronchioles At the end of each bronchiole there is an air sac The air sac is made up of several alveoli The alveoli have capillaries wrapped around them Capillaries Alveoli Trachea Bronchioles Blood cells with Oxygen Oxygen in CO2 out Blood cells with CO2

4. Why would the alveoli have capillaries around them? This ensures that gas can pass through the walls of the capillaries exchanging Carbon Dioxide for Oxygen The alveoli and capillaries in the lungs represent the point where the Respiratory and Circulatory Systems interact.

5. When you inhale muscles in between your ribs contract and the diaphragm (a muscle below your lungs) contracts. When you exhale the muscles in between your ribs relax and the diaphragm relaxes.

6. What can make the Respiratory System not work like it should?

7. Asthma - respiratory disease in which certain airways in the lungs become constricted Bronchitis – mucous accumulates in the bronchioles and does not allow as much air to pass through Emphysema – the alveoli lose their elasticity Pneumonia – the alveoli fill with liquid (pus, mucous etc)

10. Facts about smoking Toxic substances in tobacco (over 4,000 chemicals) bother the lining of bronchi and destroy cilia. Why would this be bad? More susceptible to infections/diseases caused by air- borne particles. Increases the risk to have cardiovascular disease – higher rate of heart attacks than a normal person

11. Nicotine – the main substance in a cigarette Why is nicotine so addictive? Absorbed easily through the skin, increases levels of dopamine (feel good hormone) The problem is: dopamine wears off after a short bit and the body craves more nicotine. Person who smokes 30 cigarettes (pack and ½) in a day gets 300 doses of nicotine a day.