• Define the terms intrapleural pressure and intrapulmonary pressure

Intrapleural pressure - this reffers to the pressure between the pleura so within the pleural cavity.

at resting the pressure is = - 5cm H20

during inspiration the pleura get pulled apart and th enegative pressure then increases to = -7.5cm H2O

intrapulmonary pressure - The force exerted by gases within the alveoli is called intra-alveolar (intrapulmonary) pressure

at rest = 0 then this pressure increases during inspiration to -1 then during expiration = +1

• Explain what causes intrapleural pressure

the fluid bond between the visceral and parietal pleura and the parietal pleura's adhesion to the body wall and diaphragm so basically the fluid betwen the two adheses them together and causes the lung to stick onto the thoracic wall, then during inspiration and expiration there is a change in pressures

what about lymphatics within that?^

• Describe the processes involved in quiet inspiration and expiration

upward and downward movement of the diaphragm creates pressure, enough to suck in air then expulse it out into the enviroment.

• Describe the processes involved in forced inspiration and expiration

this requires more than just diaphramatic movement. it requires use of muscles which move the ribcage upwards and outwards and pulls it down and in again.