During quiet inspiration, Xena’s intrathoracic and intrapleural volumes will increase while her intrathoracic and intrapleural pressures will decrease. This process is known as negative pressure ventilation (NPV) because the inspiratory force is generated by a fall in thoracoabdominal pressure, rather than an active muscle contraction.
To understand this process it helps to look at how each of these parameters are affected during quiet inspiration. When Xena takes a breath in her diaphragm contracts downwards, creating a decrease in pleural pressure which causes air to flow into the lungs. This inflates the alveoli and increases both the intrapulmonary volume as well as its associated pressure. At the same time, this expansion of air within the lungs also causes an increase in thoracic volume due to its elasticity.
Describe the changes in Xena’s intrathoracic and intrapleural volume and pressure during quiet inspiration.
The corresponding changes in pressures are what makes NPV different from other types of breathing such as positive-pressure ventilation (PPV). As Xena breathes in she will experience a drop in both pleural and thoracoabdominal pressures since there is no active muscle contraction pushing out against them; instead, only gravity is acting on her chest wall and abdomen. This results in lower levels of intrapulmonary and thoracoabdominal pressures compared to when she exhales.
Overall then, during quiet inspiration Xena’s intrathoracic and intrapleural volumes will increase while her intrathoracic and intrapleural pressures will decrease – all thanks to NPV!
1) https://wwwncbinlmnihgov//books/NBK539083/#chapter2 . Negative_Pressure_ Ventilation < ; br> ; 2 ) http : //webaludelgadocolombogeduco/revintercontinentalderadiologia//html / 2019 / vol25no3Art7-enpdf < ; br> 3 ) https : //wwwsciencedirectcom/topics/medicine -anddentistry/negative -pressureventilation