Biology- Artifical Breathing Aids& Breathing (LUNGS)

'Iron Lung was used for people who were paralysed (Injury or polio). A person would lay with their chest in a metal cylinder, a vacuum was formed creating a negative pressure- forcing it on the chest and forcing air out.

Positive pressure aids are now smaller and easier to manage at home and can be linked to computers to monitor how well they are working.

If the alveoli are damaged, the surface area in the gas exchange is reduced. If the tubes leading to the lungs are narrowed, less air can pull the ribcage up & out.

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  • Created by: Katie
  • Created on: 20-03-13 18:55

B3 Exchange in the gut

  • Food  digested into small soluble molecules. Small intestines- solutes absorbed into the blood- Villi line the inner surface of small intestine and exchange surface for food molecules.
  • Villi- greatly increase surface area. Walls are very thin and many capillaries are close to the wall
  • Active Transport- allows cells to take in substances against  concentration gradient.
  • It uses energy from respiration. Ions from dilute solutions, like sugar- can be absorbed by active transport.
  • Osmosis- is the movement of water. It is the diffusion of water across a particaly permeable membrane. It moves water from a high water concentration to a region of lower water concentration.
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