Effects Intrapleural Pressure

Question 1

volume is inverse to

Answer 1

• pressure

Question 2

during inspiration

Answer 2

- thoracic pressure decreases 
= have a massive venous return to lung
- temporary pooling of blood during inspiration
- flow to the LA is decrease
- flow to the LV is also decrease
- decrease CO
- decrease BP by 10mm Hg
- increase HR phenomenon called paradoxical fall of blood pressure during inspiration

Question 3

during expiration

Answer 3

inverse to inspiration

Question 4

valsalva manuever

Answer 4

• squeezing lung
  in the BEGINNING: decrease BP and increase HR
  LATER: increase BP and decrease HR
  END: decrease venous return to the lung due to decrease pressure gradient
  decrease flow to the heart
  decrease BP
  increase HR causing fainting

Question 5

positive end-expiratory pressure (PEEP)

Answer 5

• volume cycled most common
• is applied at the end of the expiratory cycle to decrease alveolar collapse
• goal is help the patient to empty his alveolus

Question 6

simple pneumothorax (losing the negative intrapleural pressure, losing lungs ability to expand causing the lung to collapse)

Answer 6

• due rupture blebs opening air outside
• increase intrapleural pressure (negative pressure) as it becomes more negative the becomes more expanded, it lose its expanding ability because intrapleural pressure became more negative as atmospheric pressure
• decrease lung recoil to zero as lung collapse
• chest wall expands