Yr8Erin

= Year Eight science 2012 =
 * Ecology **

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 * My video about the beneficial and harmful effects of micro-organisms **

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 * My video about adaptations**


 * All Systems Go **

The respiratory system, labelled


 * Explain how air enters and exists the lungs. **

When you inhale, you cause the diaphragm to to contract, flatten and move down. The external intercostal muscles also contract, which causes the ribcage to lift upward and outwards. This increases the volume in the thorax and decreases the air pressure, which allows fresh air to be drawn into the lungs.

When you exhale, you cause the diaphragm to relax and move upwards. The intercostal muscles also relax and cause the ribcage to drop down and inwards. This decreases the volume in the thorax, which allows the air in the lungs to push out.


 * Explain the process that occurs inside the alveoli. **

The alveoli is located on the ends of the bronchioles, and are tiny air sacks. They inflates during inhalation and deflate during exhalation.

The alveoli are surrounded by many capilliaries, and they are very important during the gas exchange. As there are high oxygen and low carbon dioxide concentration within the alveolus, and low oxygen and high carbon dioxide concentration within the capilliaries, the process of diffusion is able to occur. The oxygen that we breathe in makes its way to the alveolus, and then to the area of low oxygen concentration inside the capilliaries, where the oxygen we breathe in turns the low oxygen areas to areas of rich oxygen. In turn, the carbon dioxide that is inside our body is exhaled, travelling first from the capilliaries to the alveolus and our of our blood stream.

Both processes occur in unison, so as new oxygen is entering the body, the carbon dioxide leaves.


 * My Video on the respiratory system: **

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 * My Video all about Victor Chang:**

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Careers in Science Dietitian A Dietitian is someone who works in the field of health, focusing on food and diets. They work closely with doctors and other health care professionals to ensure that their clients are receiving the right care. Most of their work entails educating people about diets. They make sure that someone who has been diagnosed with a disease such as diabetes or kidney problems know exactly what they can and can’t eat. All dietitians need to have a very good knowledge about the effects food has on the body, as well as other skills depending on the specific field that they work in.

Marine Biologist A marine biologist works in the field of marine biology, as field very large due to the fact that there is lots of water on the earth. It entails everything from studies of ocean currents to analysis of creatures. Most marine biologist pick just one aspect of marine biology to focus on, such as rehabilitation of injured marine mammals. However, marine biologists do not handle the marine mammals, as zoologists usually handle them. Most marine biologists get to travel to interesting places and work with cutting edge equipment, while others work in labs learning about specific ocean organisms, and some work in the field of education.

** My Video about adaptations **