Effect of lung disease 🫁

• breathing out as hard as you can is called forced expiration (fev)

  Describe and the explain the mechanism that causes forced expiration!

  Contraction of the inner intercostal muscles

  Relaxation of external intercostal muscles

  Causes a decreased volume of air in the chest

  So air is pushed down the concentration gradient.
• How would you calculate the percentage decrease?

  percentage change - difference Divided by original x100

  4.2 divided by 0.8

  Then divide that by 4.2 and x 100

  That gets you 80.9 which rounds to 81%a

  Take that of 100 to find the decreased amount of 19%

  
• The people in group B were recovering from an asthama attack explain how an asthma attack caused the drop in mean FEV showing in the figure!

  The muscle walls in the bronchi will contract

  the Muscle walls then also produce a large amount of mucus

  So the volume of the airways is reduced

  Therefore the airflow is reduced as a whole
• What precautions can be made to ensure the mean value of FEV1 is reliable?

  take a large sampling

  repeating the readings
• Explain the importance of determining the mean fev1 value of 25 year olds in this investigation

  In order to compare it with the effect of smoking
• The mean fev1 value of non smokers decreases after the age of 30

  Explain why.

  inner intercostal muscles are less affective/efficient
• One of the severe disabilities that results from emphysema is that walking upstairs becomes difficult

  Explain how a low FEV1 could cause this disability.

  Less carbon dioxide is removed

  Less oxygen is taken in by the blood into the cells

  So less aerobic respiration takes place

  And as a result less energy is released for movement
• Some scientists concluded that the rise in reported cases of miners lung after 1992 shows that disease takes a long time to develop

  Evaluate the conclusion

  The graph shows fluncutations

  The correlation does not support the causation

  There is new diagnosis methods
• A person was sitting at rest and breathing normally. A recording was made of the changes of flume of air over 10 seconds

  Describe the part played by the muscles that bring about change between 3 and 4 seconds

  Muscles are used in breathing to relax

  
• Descrine how an increase of lung volume Leads to air entering the lungs.

  Produces a lower pressure and moves down a concentration